Indian Welding Journal - The Indian Institute of Welding

Indian Welding Journal Chief Editor Dr. T. K. Pal Professor Metallurgical and Material Engg. Department Jadavpur University, Kolkata – 700032 Phone & Fax : 033-24146317 (O) E-Mail :[email protected]

Joint Editors Mr. Rahul Sengupta Chairman Meeting and Publication Commiittee Indian Institute of Welding

Dr. Shaju Albert Head, Materials Technology Division Indira Gandhi Centre for Atomic Research, Kalapakkam, Tamilnadu

Editorial Board 1.

Mr. P. K. Das, Immidiate past Chief Editor, IWJ and Vice president of IIW.

2.

Dr. A. K. Bhaduri, Associate Director, Indira Gandhi Centre for Atomic Research, Kalapakkam, Tamilnadu - 603 102.

3.

Dr. G. Madhusudan Reddy, Scientist 'G', Group Head, Metal Joining Group, Solidification Technology Division, Defence Metallurgical Research Laboratory (DMRL), Hyderabad, Hyderabad – 500 058.

4.

Dr. Amitava De, Professor, Mechanical Engineering Department, In-Charge, Structural Integrity Testing & Analysis Center (SITAC); Central Workshop, IIT Bombay, Powai - 400 076.

5.

Dr. V. Balasubramanian, Professor and Director, Centre for Materials Joining& Research, Department of Manufacturing Engg., Annamalai University, Chennai.

6.

Dr. Santanu Das, Professor and Head, Mechanical Engg. Department, Kalyani Government Engineering College, Kalyani, West Bengal.

7.

Dr. G. Padmanabham, Associate Director, International Advanced Research Centre for Powder Metallurgy & New Materials (ARCI), Hyderabad.

8.

Dr. Mahadev Shome, Head, Material Characterization and Joining research group, R&D, Tata Steel, Jamshedpur-831 001.

Special Invitees 1.

Dr. Stan David, Corporate Fellow and Group leader (Rtd.) Oak Ridge National Laboratory, Consultant, USA.

2.

Professor W. Fricke, Hamburg University of Technology, Germany.

3.

Professor Dietrich Rehfeldt, Leibniz University, Hanover, PZH, IW, Joining of Materials.

Representing American Welding Society Andrew Cullison & Jeffery Weber 11

EDITORIAL

EDITORIAL First of all I would like to thank council members of The Indian Institute of Welding for giving me the opportunity to act as Chief Editor of Indian Welding Journal from January issue. You will agree that the economic growth of India over the period has changed her position and has involved changes in her industrial structure. These changes greatly affect the status of welding engineering and technology in the present industrial society. The Indian Institute of Welding has also decided to restructure itself to adopt to these new environments. We have come round an eventful year for the Indian Institute of Welding as well as Indian Welding Journal. Our institute hosted the prestigious event “64th Annual Assembly & International Conference of the International Institute of welding, Chennai, India, July 17-22, 2011”, being held for the first time in our country and our annual assembly "NWS 2011" during December 16-18, 2011 at Bhilai. IWJ provides a forum for the multidisciplinary subjects within joining of materials and helped to encourage developments and information exchange of important work within the field. In this issue, there are three awarded technical papers which would be of interest to both welding and material engineers. We have the pleasure to put on records our compliments to Dr. R. S. Parmar, who made valuable contribution to welding technology and the institute, for being chosen to receive the “Life time achievement award” and Mr. P. K. Das, immediate past Chief Editor and Vice President of our institute, for being promoted the journal a new look idea and making them available for advertisement and sponsorship. IWJ is proud to welcome the new board members, who are recognized for their significant contribution towards the growth of welding technology. It is my hope that the new editorial board will play an important role and with the support from related organizations, contribute to the prosperity and welfare of human being and of global society. The January issue of the journal is coming out during mid February. Late receipt of materials for publication has caused this delay which we sincerely regret. The cooperation and ideas from all members shall continue to make the journal more valuable in future. Before we end, we from IWJ wish all our readers, home and abroad, a very Happy, Prosperous and eventful 2012.

T. K. Pal Chief-Editor Email: [email protected]

13

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

HONY. SECRETARY GENERAL'S DESK Dear Members, At the outset I must congratulate Bhilai Branch and the organising committee of NWS-2011 for the very successful way they have organized our most prestigious annual event the National Welding Seminar-2011 in association with Bhilai Steel Plant. In this connection I must acknowledge the generous and whole hearted support received from Shri Pankaj Goutam, Chief Executive officer and other senior officials of Bhilai Steel without whose help and hospitality the seminar would not have been such a success. On an invitation from the International Institute of Welding a three member team comprising of M/s. R. Ravi, President IIW-India, B. K. Mishra, Chairman, ANB-India and the undersigned, attended the IIW Intermediate meetings including Working Group Regional Activities, Commission meetings and IAB meetings held in Paris during January 2012. During the WG-RA Meeting majority of I1W Officials had highly appreciated the IIW-India for successful conduction of last 64th Annual Assembly & International Conference held at Chennai during July-2011. I am pleased to inform that following our earlier application for holding IWC-2014 in India, the Governing Council of IIW have awarded organization of the International Welding Congress 2014 to IIW India. This is scheduled to be held at New Delhi from 6th to 8th March-2014. We have given a presentation in the WG -RA Meeting on IC-2014 regarding the progress of the event. The members present appreciated the progress. Further the IAB Group B Committee has extended the time for application for IWCP diplomas through Transition arrangements for IIW India up to 31st July 2012. Our MES assessment activities have been progressing well. During the period from October to December-2011 out of 934 assessments received for various courses under fabrication sector, 781 candidates were assessed of which 765 candidates had passed. Under IIW-India's National Welders Training and certification programme during October to December-2011, 3 new Welder Training Institutes applied to us for becoming Authorised Training Institute for conducting NWTCS program. I am also pleased to inform that our newly formed ANBCC has received preliminary approval from the IAB for operating IIW's manufacturers Certification Scheme in India and that we have been able get our first client in Delhi for conducting ISO 3824 audit. Our ANB -India division from November-2011-January-2012 have organized a total of five Refresher Courses held at Kolkata (2nos), Baroda, Chennai and Delhi. A total of 60 candidates had appeared in these courses and for award of the International Welding Personnel Diplomas. Best Regards.

Parimal Biswas [email protected]

14

IIW NEWS

IIW NEWS To commemorate the event a souvenir & CD, containing

NATIONAL WELDING SEMINAR – 2011

all the selected Technical Papers of NWS-2011, were

HELD AT BHILAI

released by the dignitaries.

REPORT FROM IIW BHILAI BRANCH

During Inaugural Session, various welding Awards,

The National Welding Seminar – 2011 (NWS-2011) was

institutionalized by IIW-India, were ceremoniously given

organized by the Bhilai Branch of the Indian Institute of

away for the papers presented during the last welding

welding in association with Bhilai Steel Plant (SAIL)

seminar by the IIW-India president Shri R. Ravi & Chief

during December 15th – 17th, 2011 and this was the

guest Shri Pankaj Goutam that also includes the best

third occasion the branch hosted this mega event after a

welding Engineer and best welders awards. The

gap of five years. The theme of the seminar was

prestigious Life Time Achievement Award for year 2010-

“Welding Science & Technology in Infrastructure

11 was given away to Dr. R. S. Paramar, Ex. Prof. of IIT,

Industries”. While the Inaugural session held at Kala

Delhi.

Mandir Auditorium, the technical sessions and

The two prominent memorial lectures viz Keith Hartley

concluding session were held at Bhilai Niwas, both within

Memorial lecture & Dr. Placid Rodriguez Memorial lecture

the Bhilai Steel Plant township. Around 225 delegates

were delivered by Dr. T. K. Pal, Prof. of Jadavpur

were drawn from a variety of fields like Educational

University & Dr. G. D. Janaki Ram, Prof. of IIT, Madras on

Institutions, R & D, Industrial Consumables,

topics 'Development of welding technology for

Manufacturer etc. Altogether 40 papers were accepted

auto-motive industries' & 'Emerging concepts in

and 36 papers were presented during the seminar on a

welding research, respectively.

wide range of topics.

Coming to Technical Sessions about 36 papers were

The Chief Guest Shri Pankaj Goutam, Chief Executive

presented in two parallel run sessions. The sessions

Officer of Bhilai Steel Plant and Chief Patron of Bhilai

were chaired by S/Shri N. K. Sarkar, V. S. Galgali, H. V.

Branch of IIW, underlined the rising importance of

Sharma, C. K. Datta, P. K. Das, Dr. G. L. Datta, A. B.

welding in the infrastructure Industry and stressed the

Purang, Dr. Madhusudan Reddy, H. K. Sethi & S. N. Singh

need for constant updation of knowledge related to all

all prominent persons in their chosen field of

aspects of welding. In the same vein Shri R. Ravi,

professions.

President (IIW-INDIA) while enumerating the role of IIW in keeping the industry informed and guided in the

The papers covered the wide spectrum right from

latest development taking place in the field.

Research, New application, New developments, Economy & Health concern related to various aspect of

Other speakers including President IIW – Bhilai Branch

welding.

Shri P.K. Singh, ED (Works) BSP and Secretary General of

The speakers were all experts in their particular areas

IIW-INDIA Shri Parimal Biswas also stressed the importance of such events for better applicability of

and did a splendid job in compiling their thought &

welding as a Science & Technology.

research into their papers.

At the outset, Shri Debasish Thakur, Chairman (IIW-

Each paper was judged by 3 persons including the

Bhilai Branch) and GM (Utility) BSP, welcomed the

session chairman and 2 delegates from audience. These

dignitaries, distinguished guests & delegates and briefed

evaluation sheets have been handed over to Dr. Shaju

the gathering about the Seminar and the action role

Albert, Chairman, Technical Committee (IIW-INDIA) for

being played by the Bhilai Branch in spreading the

declaring the results.

objective of IIW-INDIA. 15

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

The sumptuous lunches & dinners assisted by cultural

Structural (Plate) Welding category and Mr. Vinod

programmes at night have only helped in assimilating

Kumar, R. Parmar of L&T, Baroda was declared as the

these technical contents easily.

Best Welder in the Pipe Welding category. Each of them was given an Award of Rs.5000/- in cash and a

Valedictory function was presided over by Dr. R. S.

certificate.

Parmar and concluding remarks was summed up by Shri Parimal Biswas on behalf of the council.

All the Awards sponsored by ELCA Laboratories, Thane, Maharashtra were given to the winners during the

The proceedings of the entire activity were conducted by

Inauguration ceremony at the National Welding Seminar

Shri G. M. Arun Kumar, DGM (MARS); Mrs. Manju

held at Bhilai on 15th December, 2011.

Haridas, AGM (ERS); Shri V. K. Ogale, Sr. Mgr. (RMP-1)

IIW MES AB:

and Shri Umesh Malayath, Jr. Mgr. (CAS) while the vote of thanks was proposed by Shri Ajay Bedi, Hony

A total number of 372 candidates assessed under this

Secretary (IIW-Bhilai Branch).

scheme at various ITI in Gujarat under the active

During the seminar, the 280th Council Meeting and

leadership of Mr. R. R. Vishawakarma, Gujarat State

Annual Members Assembly were also held.

Coordinator & Authorised Assessor

The work of various committees, formed to make the event a grand success, was highly acknowledged that also

BRANCH ACTIVITY REPORT

includes S/Shri S. K. Bansal, H. K. Sahu, R. K.

Bisare, M. R. K. Sariff and D. Anand.

REPORT FROM BANGALORE BRANCH

REPORT OF THE BWE & BW COMPETITIONS,

1.

jointly conducted on 17th Nov 2011 by Indian

2011

Society for Non-Destructive Testing [ISNT], Society

The National Level Competitions for the Best Welders

for Indian Aerospace SIATI Blr, where-in Padmashri

and Best Welding Engineer of the year, 2011-12 was held

Dr. C. G. Krishnadas Nair was facilitated; and the

at the Welding Reclamation Shop of the Bhilai Steel

Branch Chairman, Mr. N. Ramesh Rao delivered the

Plant, Bhilai on 13th December, 2011 and was conducted

Key-Note Address.

by Mr. N. K. Sarkar. 2.

Out of 11 branches, only 7 branches viz. Baroda, Bhilai, Chennai,

Program on “Advances in Welding & Testing”

Jamshedpur,

Kolkata,

Mumbai

Program on “Copper Welding, Brazing & Soldering” was conducted on 25th Nov 2011

and

jointly with Indian Copper Development Centre,

Visakhapatnam participated in this year's competition,

where-in the Branch Chairman Mr. N. Ramesh Rao

there were only five candidates in each category.

presented a paper on “Considerations in imple-

IIW Mumbai Branch assisted by Mr. S. C. Mitra and Mr. T.

menting Copper Welding Procedures” .

K. Mitra both from Kolkata branch and Mr. S. C. Tuteja

3.

from Bhilai.

The Branch Committee members visited Mysore & Dharwad Regional Centres for Skill Development for

Mr. Biswajeet Paul of L&T Ltd., Mumbai was declared as

promoting Welding Training Programs; this was

the Best Welding Engineer. He was given an AWARD of

arranged by the Branch Hony Secry Mr SV Dilipan.

Rs. 7,000/- in cash and a certificate. He was registered as

4.

a free delegate for the NWS.

The Branch Committee members visited Advanced Simulator Training Facility for Skill Development for

Mr. Roque Fernandes of Don Bosco Maritime Academy,

promoting Welding Training Programs; this was

Mumbai was declared as the Best Welder in the

arranged by the Branch Hony. Secy. Mr. S. V. Dilipan 16

IIW NEWS

REPORT FROM BARODA BRANCH I.

Director, Selectarc Industries, France, on 14th December 2011 at Hotel Surya Palace. 85

One-day Seminar

Participants attended.

Organised Seminar on "Welding in Pressure

3.

Vessels Industries" - as 13th Foundation Day

“Seam less flux/metal cored wires suitable for pipe line, offshore & shipbuilding

Celebration, held on 15th October 2011 at Hotel

applications” Presented by Mr. Martin Schnirch,

Surya Palace.

Sales Director & Mr. Andreas Holzner, Head of

The Seminar was inaugurated by lighting the lamp

Quality and Application Management Drahtzug

by Chief Guest Mr. R. K. Batra & other dignitaries

Stein wire & welding (German Company).

present on dias. On this occasion, the Souvenir

III. Workshop Training :

covering technical papers, advertises & IIW

Following workshop training programmes were

informations etc., was released by Chief Guest. The Chief Guest

conducted

Mr. R. K. Batra, Exe. Director

1.

(Project & Construction, Engineers India Ltd ) in his

WPS/PQR workshop from 17th to 18th December

inaugural speech emphasized on the need of

2011 at Hotel Sayaji, Vadodara. Total 26

welding knowledge sharing to various professionals

participants attended the workshop. The workshop

in the construction industries and training to the

conducted was to educate the welding engineers

welding inspectors as well as welders to improve

on the different aspects of preparing WPS/PQR as

upon the skill and performance to achieve the best

per ASME Section IX Code requirements. At the end

quality standards.

of the workshop participants were given case studies to prepare the WPS on their own and

The Convenor of the seminar was Mr. D. C. Mehta

present it to all.

and the technical session was chaired by Mr. R. R. Chhari. The Seminar received overwhelming

The Convenor of the programme was Mr. Kashyap

response from various advertisers & sponsors.

Bhatt, supported by Mr. Vijay Patel, Mr. R. R. Chhari and Mr. B. S. Kandpal as faculties and evaluation

The Seminar was Sponsored by M/s Vijay Tanks and

team members.

Vessels (Baroda) and by M/s Satkul Enterprises Ltd, (Ahmedabad).

2.

NDT Level II (Visual Testing) course from 23rd to 25th December 2011 at Hotel Nidra, Vadodara. The

II. Technical Lectures :

training for NDT Level II (Visual Testing) was

Following Technical Lectures were organized :

organized as per ASNT recommended Practice-SNT-

1.

“Comparison between ASME and EN

TC-1A : 2006. Total 18 Participants attended the

requirements for Welders and Welding

Training Programme.

Procedure Qualification” by Mr. Mahendra

The Convenor of the programme was Mr. Kashyap

Shiroya (QMOS-LeveIII Inspector) and Mr. Sunit

Bhatt.

Kumar (PED Inspector) from M/S. Bureau Veritas

3.

(India) Pvt. Ltd., Baroda, on 14th July 2011 at Hotel

Transition Route from 22nd to 26th November 2011

Revival Lords INN. near Sayaji Garden, Vadodara.

at GETRI, Baroda. 19 participants attended the

67 Participants attended. 2.

47th IWE/IWT Certification Programme through

programme.

“Welding of Nickel and High Alloy Steels” Presented by Dr. K. Manfred Rostek, Technical 17

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

competition. Written Tests and Viva were conducted

IV. Awareness of IIW Activities (Promoting

for the Best Welding Engineers and for the welders

Welding Science & Technology)

category practical test coupon welding and viva

Presentation of IIW India activities (special

were conducted. The following candidates were

emphasis on AMIIW exam and Membership) were

declared winners after the evaluation procedure for

conducted by Dr. Vishvesh J. Badheka, Hon. Joint

the branch level competition :

Secretary of IIW Baroda Branch and in Industries

1.

by Mr. B. S. Kandpal at following academic and R &

Mr. Tushar Koradia - L&T Ranoli – Best welding

D institutes:

Engineer

Mechanical Eng Dept; U V Patel College of Eng &

Mr. Mukesh R Valand – Inox India – Best welder for

Technology, Ganpat University, Mehsana. More

structural Welding

than 80 students of Final & Pre final year

Mr. Vinodkumar R Parmar – L&T Ranoli – Best

Mechanical and M.Tech (Advance Mfg. Technology)

welder for Pipe Welding.

students were attended. Presentation was of about

The Winners of the branch level participated in the

1 hr. followed by 30 min. questions answers. 2.

National Level Competition held at Jamshedpur

ITER-INDIA, IPR, Gandhinagar; 20 Scientist/

from 13th to 15th December 2011. Results are very

Engineers of ITER India were attended. Mr. Mukesh

pleasing for Baroda Branch.

Jindal of ITER INDIA who is already member of IIW

Mr. Vinodkumar R. Parmar declared Winner of the

Baroda, is nodal person to promote IIW activities. 3.

Best Welder competition; while Mr. Tushar Koradia

Diploma Mechanical Engineering (Polytechnic) and

was declared as runner up of the Best welding

M.E (Welding Technology) of The M. S. University of

Engineer competition.

Baroda. 4.

5.

VI. Industrial Visits :

Diploma Fabrication Technology and Diploma Mechanical Engineering at Government Poly-

Industrial Visit was made to M/s Hindustan Dorr

technic, Bhavnagar on 3rd December 2011

Oliver, Ahmedabad on 1st October 2011. A total 20 members visited the HDO.

Electrical Research and Development Association (ERDA), on 14th December 2011.

REPORT FROM CHENNAI BRANCH

V. Best Welding Engineer And Best Welder Competition -2011

I.

IWE/IWT ANB Programme during 11th to

Best Welder and Best welding Engineer competition

15th October 2011

was held at M/S Avadh Industries – Makarpura on

The forty fifth Certification Programme (IWE, IWT)

11th November 2011. The competition was

of International Institute of Welding was held from

conducted and examined

by Mr. Jayesh Patel,

11th to 15th October, 2011, at the lecture hall of the

Mr. Kashyap Bhatt, Mr. D. V. Acharya and Mr. B. S.

ISNT Chennai Chapter. Six participants attended the

Kandpal.

programme.

There were 4 participants from different industries

II. Best Welder/Best Welding Engineer Contests

for Best Welding Engineer Competition and 2

The contests for the Best Welder (Structural and

participants for Best Welder (Pipe & Plate)

Pipe Welding) and Best Welding Engineer were held

18

IIW NEWS

on 12th November, 2011, at the L&T - Construction

welder contests was held on Saturday, the 10th

Skills Training Institute, Kancheepuram, Chennai.

December, 2011 at Hotel Radha Regent, 171,

Nine participants for structural welder, 11 parti-

Jawaharlal Nehru Salai, Chennai. Mr. G. Ravindran,

cipants for pipe welder and 9 participants for weld-

JGM, Audco India Ltd, Maraimalainagar, Chennai

ing engineers participated in the contest. Shri. V.

was the Chief Guest and distributed the awards to

Sundaramurthy, Principal, L&T Construction Skills

the winners.

Training Institute inaugurated the contests.

V. Technical Lectures

Shri. R. Ravichandran, was convener of the BW & BWE committee, and supported by Shri. S.

IIW-India, Chennai Branch organised two evening

Chandran, EC member.

technical lectures on 10th December, 2011 at Hotel Radha Regent, Chennai on the following topics. The

Shri. R. Mekkavan of BARCF, Kalpakkam won the

programme was sponsored by FSH welding India

Best Structural Welder, Shri. Yesuraj, of TPPC

Pvt. Ltd.

Division, Larsen & Toubro Ltd, Vemagiri, AP won the

1.”Welding of nickel alloys & SS alloys

Best Pipe Welder and Sri. V. Mohanraj, of L&T HCP Division; Manapakam, Chennai, won the Best

suitable

Welding Engineer contests respectively. The branch

applications” by Dr. K. Manfred Rostek,

level winners were nominated for national level

Technical Director - FSH Welding Group, France.

contest held in Bhilai on 13 & 14 December 2011.

for

High

temperature

2. “Seamless flux/metal cored wires suitable for pipe line, offshore & shipbuilding

III. One Day WELDING Course in TAMIL

applications” by Mr. Martin Schnirch, Sales

A One day welding course in Tamil was held at hotel

Director & Mr. Andreas Holzner, Head, QC M/s

Radha Regent, 171, Jawaharlal Nehru Salai,

Drahtzug Stein wire & welding.

Chennai on November 19th, 2011. 107 participants

VI. IWE/IWT ANB Programme during 19th to

from Chennai and neighboring areas attended the course. Sri. Joseph Amalraj, L&T/HCP division

23th December 2011

Chennai, inaugurated the course. Sri. V.

The forty eighth Certification Programme (IWE,

Muralidharan, Vice Chairman – IIW India Chennai

IWT) of International Institute of Welding was held

Branch was the course director.

from 19th to 23rd December, 2011, at the lecture

In the evening a weld quiz programme for the

hall of the ISNT Chennai Chapter. Thirteen

course participants was conducted by Sri R.

participants attended the programme.

Ravichandran, EC Member. Sri. R. Ravi, President,

VII. Half Day Technical Programme & Felicitation

IIW-India, distributed the prizes to the top three

to IIW EC Member.

winners. Sri. V. Muralidharan; Vice Chairman – IIW

A half day technical programme on “QA

India delivered a technical lecture on ISO

Experiences in Reprocessing Projects & J-

3834. At 19.00 hrs. the approved training body

Rod Campaign to DFRP – Experiences” was

(ATB) certificate was handed over to M/s

held at the Ramanna Auditorium, IGCAR

Cornerstone Academy Pvt. Ltd. Chennai, by the

Kalpakkam. The event was held on the 28th of

president, IIW - India.

December, 2011, (Wednesday ), from 14.00 hours

IV. BW & BWE awards function

to 17.00 hrs., to felicitate Shri P. Ram Kumar, Head, RPSD, formerly the EC Member of IIW-India,

Awards function of the best welding engineer & best

19

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

REPORT FROM KOLKATA BRANCH

Chennai Branch, on the occasion of his superannuation. Shri R. Natarajan, Director, RPG inaugurated

the

programme.

Around

The branch will organise a one day Workshop on

60

"Advancement in Welding Technology" at The

participants attended the workshop and benefited.

Institution of Chemical Engineer's Hall, Jadavpur

Eminent speakers from IGCAR/Kalpakkam

University on 25th February, 2012. As a programme, the

delivered the technical lectures on following topics.

branch is planning to celebrate Foundation Day of the Institute in a dignified manner on 21st February, 2012.

1. “QA Experiences in Reprocessing Projects” by– Dr. B. Venkatraman 2. “J-Rod Campaign to DFRP – Experiences”

REPORT FROM VIZAG BRANCH

by Shri P. Ram Kumar

The Indian Institute of Welding, Visakhapatnam Branch

Sri. T. V. Prabhu Hony. Secretary, IIW Chennai

organized a lecture on “Advanced Welding

Branch co-ordinated the entire event.

Processes” and “Emerging Welding Processes” held

the

Executive

Director

(Projects

&

Commissioning) Conference Hall on 19th December

REPORT FROM IIW DELHI BRANCH I.

at

2011 from 10.30 am to 1.30 pm. The programme was

A one day workshop on “Advances in Arc

well attended by IIW members, Vizag Steel Engineers,

Welding Technology” was organized at

M. N. Dastur & Co. (P) Ltd., Engineers and other Industry

Northern India Engg. College, New Delhi on 16th

Engineers.

November, 2011. About 100 delegates from

Lecture was delivered by the Eminent Prof Dr. R. S.

various Engineering Colleges in the region

Paramar and started with welcome address by Sri A. K.

attended the program. The lectures were delivered

Bose, Vice Chairman.

by Dr. R. S. Paramar, Dr. C. K. Datta, Mr. J. R.

Mr. M. Saibabu, Hony. Secretary, Vizag Branch informed

Prasher and Mr. Vivek Vasudeva. A lively discussion took place between the speakers and the delegates

the gathering about the IIW activities, particularly

at the end of the Technical Sessions. Certificate of

courses offered by ANB and the advantages of the

participation was given to all the attending

ANBCC.

delegates in the valedictory session.

Mr. Venkat R D, the Jt. Secretary of the IIW, Vizag Branch, proposed a Vote of Thanks.

II. The Branch Seminar of IIW - Delhi Branch has been announced to be held on 11th February, 2012 at India International Center, Max Mueller Marg, New Delhi. The theme of the seminar is “Emerging Trends in Welding Industry.”

20

LIFETIME ACHIEVEMENT AWARD

LIFETIME ACHIEVEMENT AWARDS Prof. R. S. Parmar was honoured by The Institute with the Lifetime Achievement Award at the National Welding Seminar, Bhilai held in December 2011

Dr. R S Parmar is B.E. Mechanical Engineering from

He is a Life Fellow of the Indian Institute of Welding and

Punjab University; M.E.Hons. (Production Engg.) from

The Institution of Engineers (India) and a Life Member of

University of Roorkee, and Ph.D. (Welding) from IIT,

Indian Society of Mechanical Engineers and Indian

Kharagpur. He has an experience of more than 44 years

Society of Technical Education.

in Teaching and Research in different subjects of Mech.

He is a recipient of Gold Medal from University of

Engg. particularly related to Production Engineering. He

Roorkee, K. F. Antia Memorial Prize and Col. G. N. Bajpai

served at REC, Srinagar (Kashmir) for 14 years and at

Award (Twice) from the Institution of Engineers (India)

IIT, Delhi for 21 years. After retirement from IIT, Delhi he

and Keith Hartley Memorial Award (1996) of The Indian

Joined Netaji Subhas Institute of Technology, New Delhi,

Institute of Welding. He is also a Joint winner of McKAY-

where he served in the Department of Manufacturing

HELM AWARD (1998) of American Welding Society,

Processes and Automation Engineering till Sept., 2002

Miami, USA for their paper published in Welding Journal

and was also Dean Administration for 3 years (1999-

of Oct., 1997.

2002) there.

Dr. Parmar joined IIW in 1972 as a Member and is now a

He coordinated a Collaborative Project for 5 years on

LIFE FELLOW for the past about 15 years. He has been

Underwater Welding between IIT Delhi and Cranfield

very active with IIW Delhi Branch which he joined in

Institute of Technology, Cranfield (UK). He also served as

1978 as an EXECUTIVE COMMITTEE MEMBER. In its

a Visiting Professor for one year at Brunel University,

long association of about 27 years with IIW Delhi he has

Uxbridge, London (UK).

served in every capacity viz., Member, Treasurer,

Prof. Parmar has authored 2 books on Welding, and one

Secretary, Vice Chairman, and Chairman. He has been

book on Manufacturing viz.,

elected as Chairman 6 times and is still active in

1. WELDING PROCESSES AND TECHNOLOGY, and 2. WELDING ENGINEERING AND TECHNOLOGY 3. MANUFACTURING PROCESSES AND AUTOMATION

tenure as Chairman, IIW Delhi the Institute acquired its

organizing workshops and seminars in Delhi. During his permanent premises at 705 A, Jaina Tower-I, Janakpuri District Centre, Janakpuri, New Delhi - 110 058. He has

and has published more than 100 Technical Papers in the

been actively involved in organising Branch Seminars,

National and International Journals, conferences, and

Short Courses, and One Day Workshops at different

Seminars. He has guided 13 Ph.D. (2 Iranians and 11

venues in and around Delhi.

Indian Research Scholars), 27 M.Tech. and more than 50 B.Tech. Projects on Production Engineering in general and Welding in Particular.

21

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

KEITH HARTLEY MEMORIAL AWARD 2011 Every alternate year an eminent welding professional of the country is selected for delivering the Keith Hartley Memorial Award at the National Welding Seminar. IWJ compliments Prof. T. K. Pal for being chosen to deliver the Prestigious Lecture this year at the NWS - 2011

Dr. T. K. Pal obtained his B. E. in Metallurgy from

going. He has guided 19 students for their Ph.D

Burdwan University in 1975 and subsequently

thesis and published about 110 papers in National

completed M.Tech in Mechanical Shaping and Heat

and International Journals and Proceedings. He is a

Treatment. After six month exposure in a private

founder of Welding Technology Centre at Jadavpur

foundry, he joined as a Senior Research Fellow at

University which was established in 2002. He is

Material Science Centre of I.I.T., Kharagpur. He

Course Director of Six module based Post Diploma

joined as Lecturer, Department of Metallurgical

Course in Welding Technology and Short term

Engineering, Jadavpur University in 1981 and

Course on "Welding Inspection and Testing".

completed his Ph.D (Engineering) from I.I.T.

He was Controller of Associate Membership

Kharagpur in 1987. He became Head, Metallurgical

examination of Indian Institute of Welding during

Engineering Department, Jadavpur University

the period from 1991 to 1999 and Chairman of IIW

during 1995 - 1997.

of Kolkata branch during 1999 - 2000. He has

During the last 30 years, he had been actively

received many awards for his contribution in the

engaged in Teaching, Research, Training Courses

field of welding Technology.

and Consultancy Services related to welding

He is a fellow member of the Indian Institute of

technology. He had already completed fifteen

Welding, life member of the Indian Institute of

research projects sponsored by different Central

Metals. The Institution of Engineers (India) and

Government funding authorities such as DST, CSIR,

The Indian Society for Non-Destructive Testing.

Ministry of Steel, Naval Research Board (NRB), DRDO, UGC, AICTE and Private Industries like Tata

He is at present Professor and Coordinator, Welding

Steel and BOC Ltd. Two Research projects

Technology Centre, Metallurgical and Material

sponsored by Ministry of Steel and Tata Steel and

Engg. Department, Jadavpur University and also

one research project sponsored by CSIR are on-

Technical Advisor of two private industries.

22

PROF. PLACID RODRIGUES AWARD

PLACID RODRIGUES MEMORIAL AWARD 2011 Every year an eminent Welding Engineer and Scientist below 45 years of age is selected for delivering the Prof. Placid Rodrigues Award. This year IWJ congratulates Dr. Janaki Ram for being selected to deliver the prestigious lecture this year.

Dr. Janaki Ram obtained his masters and doctoral degrees in metallurgical engineering from IIT Madras. He specializes in welding technology. From 1998 to 2005, he was in DRDO, working on indigenous development and airworthiness certification of a number of aerospace materials and components. In 2005, he went to Utah State University, USA, for his post-doctoral work in the field of additive manufacturing technologies. In 2008, he returned to India to begin a faculty position in the Department of Metallurgical and Materials Engineering, IIT Madras. Since then, Dr. Janaki Ram has been teaching welding processes, welding metallurgy and additive manufacturing courses at IIT Madras. Dr. Janaki Ram has been actively involved in welding research for more than a decade. His research addresses both fundamental and applied aspects of welding. He has published more than 75 papers in various international journals and conferences.

23

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

List of Award Holders for the year 2011 Sl. No.

Award Name

1

2

Award Amount

Sponsorers

Sponsors Representative If Attending

Awarded To

Life Time Achievement Award 2010-11

Silver Salver

IIW Head Office

Dr. R. S. Parmar

Keith Heartley Memorial Lecture-2011

Silver Medalion

M/s.GEE Ltd Mumbai

Dr. T. K. Pal

Subject Of The Award Paper

3

Prof. Placid Rodriguez Memorial Lecture-2011

Rs.10,000/-

IIW-Chennai Branch

President-IIW

Dr.G.D.Janaki Ram, Asst. Professor, Dept. of Metallurgical and Materials Engg. Indian Institute of Technology, Chennai-600 036

4

Minati Bhattacharjee Memorial Award for Excellence -2011

Trophy

Mr. R. R. Bhattacharjee, Fellow Of The Institute of India

President, IIW-India

IIW-India Kolkata Branch

Best Performing Branch For The Year 2010-11

5.

Esab India Award (Best Technical paper across all categories)

Rs.20,000/-

Esab India Ltd. Chennai

Ms. Girish Kumar Padhy, V. Ramasubbu, SK Albert N. Murugesan and C. Ramesh of Material Joining Section, IGCAR, Kalpakkam

Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

6.

I.T. Mirchandani Memorial Research Award

Rs. 10,000/-

Ador Welding Ltd. Mumbai

M/s. P. Venkataramana & G. Madhusudan Reddy of Mahatma Gandhi Institute of Technology Gandipet and Defence Metallurgical Research Laboratory, Kanchanbagh Hyderabad

Dissimilar Metal Gas Tunsten Arc Weldments of Maraging Steel and Medium Alloy Medium Carbon Steel effect of Post weld head treatments

7.

H.D. Govindraj Memorial Research Award

Rs.10,000/-

Weldcraft Pvt. Ltd. Bangalore

M/s. G. Madhusudhan Reddy and P. Vankata Ramana of Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad and Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad

Dissimilar Metal Friction Welding of Maraging Steel with Nickel as an inter layer.

8.

Sharp Tools Award 1 (1st best paper in Welding Fabrication and Practices)

Rs.6,000/-

Sharp Tools Ltd. Coimbatore

President - IIW

M/s. Aravinda Pai, T.K.Mitra T. Loganathan & Prabhat Kumar of Bharatiya Nabhikiya Vidyut Nigam Limited (Bhavini) Prototype Fast Breeder Reactor (PFBR) Project Dept. of Atomic Energy Kalpakkam - 603 102

Challenges in Welding and Fabrication of Shell Assemblies of 500MWe Prototype Fast Breeder Reactor Steam Generators

9.

Sharp Tools Award 2 (2nd Best Paper in Welding Fabrication and Practices)

Rs. 4000/-

Sharp Tools Ltd. Coimbatore

President - IIW

M/s. Satinder Pal Singh, Amandeep Singh, Sunny Soni, Manadar Gaddu, Sanjeev Padvanda, Nishant Shah, A.D. Bhathena, L.S.Rao, Naresh Dhir and H. T. Naik of Larsen & Toubro Ltd., Modular Fabrication Facility, Hazira.

Optimization of Groove Design & Backing Methods to enhance the Productivity of Structural Tubular Welds of Jacket Legs and Piles

24

AWARDS

List of Award Holders for the year 2011 contd... Sl. No.

Award Name

Award Amount

Sponsorers

10.

Panthaki Memorial Award (Welding of Non-ferrous Metals)

Rs. 5,000/-

11.

EWAC Alloys Award (Best Paper in Reclamation and

12.

Awarded To

Subject Of The Award Paper

Bakshi Chempharma Equipments Pvt. Ltd. Mumbai

M/s. V.S.N. Venkata Ramana K. Ratna Kumar, G. Madhusudhan Reddy & K. Srinivasa Rao of Dept. of Mechanical Engg., PVP Siddhartha Institute of Technology, Kanuru Vijayawada, AP

Effect of Post Weld Heat Treatment on Microstructure and Corrosion behaviour of Dissimilar AA 2024-AA6061 GTA Welds

Rs.10,000/-

EWAC Alloys Ltd. Mumbai

M/s. Rajesh Sood and Alok Jha, Reclamation Shop Bhilai Steel Plant, Bhilai

Reclamation of Work Roll of Plate Mill of Bhilai Steel Plant

CEOBSP Award (Best Paper in Reclamation and Repair Welding in Steel Plant)

Rs.10,000/-

SAIL, Bhilai Steel Plant Bhilai

M/s. Mahendra Pal, Mayank Banjare and Susil Guria of Indian Oil Corpn. Ltd. Inspection Manager,

Root Cause Analysis of Failure in Hot and Cold Mixing Point in Hydrogen Generation Unit (HGU) due to Thermal Fatigue Phenomenon

13.

D&H Secheron Award (Best presented paper)

Rs.10,000/-

D&H Secheron Electrodes Indore

M/s. G. Madhusudhan Reddy & P. Venkata Ramana, Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad.

Friction Welding of Maraging Steel to Low Alloy Steel with Nickel as an interlayer

14.

Weldman Award (Second best presented paper)

Rs. 5,000/-

Weldman Synergic Pvt. Ltd., Kolkata

M/s. B.P.C.Rao, C.Babu Rao, S.Thirunavukkarasu, T. Jayakumar, Baldev Raj Aravinda Pai, T.K.Mitra & Pandurang Jadhav of Metallurgy & Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam

A New methodology for Qualification of Welding Procedure for Circumferential Shell Welds of Steam Generators of PFBR

15.

Best Welder (Plate) Award

Rs.5,000/-

ELCA Laboratories Thane

President - IIW

Mr. Roque Fernandez, Don Bosco Maritime Academy, Mumbai

16.

Best Welder (Pipe) Award

Rs. 5,000/-

ELCA Laboratories Thane

President - IIW

Mr. Vinod Kumar R. Parmar Larsen & Toubro, Baroda

17.

Best Welding Engineer Rs.7,000/Award

ELCA Laboratories Thane

President - IIW

Mr. Biswajit Paul, Larsen & Toubro Ltd. Mumbai

18.

Associate Engineers Rs.5,000/Award (Best M.Tech thesis submitted for award of degree in the previous academic year)

Associate Engineers Baroda

President - IIW

Mr. Hrishikesh Das submitted the best M.Tech thesis for the year 2011 under the guidance of Dr. T.K.Pal of Jadavpur University, Kolkata

19.

Weldwell Speciality Award (Best thesis in the field of welding submitted for the award of Ph.D)

Weldwell Speciality Pvt. Ltd. Mumbai

President - IIW

Dr. V. Venkateswara Rao Mechanical and Metallurgical submitted the best Ph.D Characteriation of Maraging thesis for the academic Steel to Low Alloy Steel year 2011 under the Weldments guidance of Dr. G. Madhusudhan Reddy of DMRL, Hyderabad and Dr. A.V.Sitarama Raju of JNTUH, Hyderabad

Rs.10,000/-

Sponsors Representative If Attending

25

Effects of Friction Stir Welding parameters on mechanical properties of 6063 aluminium alloy and HIF GA steel lap joint

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

List of New Members Elected during the 280th Council Meeting of The Indian Institute of Welding A. Industrial Corporate Member BANG/ICM/R-522 ESI-India Sales & Technical Branch Office MUM/ICM/R-523 John Deere India Pvt. Ltd. MUM/ICM/R-524 Jitamitra Electro Engineering Pvt. Ltd.

Bangalore Mumbai Mumbai

B. Transfer from Life Member to Life Fellow CHN/M/R-1956/L R. Ravi

Chennai

C. Life Member VIZ/M/R-10769/L MUM/M/R-10771/L CHN/M/R-10772/L VIZ/M/R-10774/L CHN/M/R-10776/L CHN/M/R-10777/L CHN/M/R-10778/L JAM/M/R-10800/L BAR/M/R-10810/L CHN/M/R-10811/L CHN/M/R-10812/L MUM/M/R-10839/L DEL/M/R-10840/L DEL/M/R-10841/L

Kadaganchi Ramanjaneyulu Ajaykumar Jadhav K. Senthilmurugan G. Mallaiah S. Muthukumar K. N. Mohan A. Manickavasagam Md. Murtuja Husain Alap Mistry Mariappan Annamalai Kasi Athinamilagi Dinesh Giri Angamuthu Kandasamy Pradeep Khanna

Visakhapatnam Mumbai Chennai Visakhapatnam Chennai Chennai Chennai Jamshedpur Baroda Chennai Chennai Mumbai Delhi Delhi

D. Member BAR/M/R-10792 CHN/M/R-10843

Vora Girishkumar M. Ponsekar

Baroda Chennai

E. Life Associate Member KOL/AM/R-10773/L Nalin Karmakar BHL/AM/R-10790/L Mandip Singh Bhogal F. Associate Member DEL/AM/R-10795 BAR/AM/R-10796 BAR/AM/R-10797 BAR/AM/R-10798 BAR/AM/R-10799 KOL/BBSR-10805

Deepak Gaba Hardik Doshi Hrushikesh H. Sangamnerkar Rahul Chauhan Yadunandan Das Narendra Kumar Pal

BAR/AM/R-10806 BAR/AM/R-10807 BAR/AM/R-10808 BAR/AM/R-10809

Hardik Dineshbhai Vyas Jaydeep Dineshkumar Patel Mitesh S. Patel Harshil Amruthlal Patel

G. Life Associate Professional Member CHN/APM/R-10788/L B. Chandramohan MUM/APM/R-10791/L Sanjeev Balan Nair DEL/APM/R-10804/L Shalender Bisht DEL/APM/R-10842/L Rajiv Kumar

H. Associate Professional Member CHN/APM/R-10784 Sundaramurthi Perumal CHN/APM/R-10785 M. Somnath CHN/APM/R-10786 C. Jayanthi CHN/APM/R-10787 M. Padmanathan DEL/APM/R-10789 Ashok Kumar VIZ/APM/R-10794 K. V. V. Srinivas Rao VIZ/APM/R-10801 Md. Darbesh Baba MUM/APM/R-10803 S. R. K. S. P. Kumar Akela BAR/APM/R-10813 Rakesh Bhatt

Chennai Chennai Chennai Chennai Delhi Visakhapatnam Visakhapatnam Mumbai Baroda

I. Life Associate BAR/AS/R-10815/L

Baroda

J. Associate KOL/AS/R-10770 JAM/AS/R-10775 BAR/AS/R-10779 CHN/AS/R-10780 CHN/AS/R-10781 CHN/AS/R-10782 CHN/AS/R-10783 CHN/AS/R-10793 MUM/AS/R-10802 BAR/AS/R-10814 KOL/BBSR/AS/R-10816 KOL/BBSR/AS/R-10817 KOL/BBSR/AS/R-10818 KOL/BBSR/AS/R-10819 KOL/BBSR/AS/R-10820 KOL/BBSR/AS/R-10821 KOL/BBSR/AS/R-10822 KOL/BBSR/AS/R-10823 KOL/BBSR/AS/R-10824 KOL/BBSR/AS/R-10825 KOL/BBSR/AS/R-10826 KOL/BBSR/AS/R-10827 KOL/BBSR/AS/R-10828 KOL/BBSR/AS/R-10829 KOL/BBSR/AS/R-10830 KOL/BBSR/AS/R-10831 KOL/BBSR/AS/R-10832 KOL/BBSR/AS/R-10833 KOL/BBSR/AS/R-10834 KOL/BBSR/AS/R-10835 KOL/BBSR/AS/R-10836 KOL/BBSR/AS/R-10837 KOL/BBSR/AS/R-10838

Kolkata Bhilai

Delhi Baroda Baroda Baroda Baroda Kolkata (Bhubaneswar) Baroda Baroda Baroda Baroda

Chennai Mumbai Delhi Delhi

26

Sumit Kainthola

Nazmul Haque Raj Kishore Jaykumar H. K. Suthar K. Hemnath Joseph Prakash Sankara M. Pandian Lalith S. Eshwar S. Udhayakumar Sandeep T. Katkar Akshay Mahesh Agrawal Sujit Kumar Behera Shambhu Kumar Abhishek Kishor B. Vinay Kumar Bibhuti Bhusan Pattajoshi S. Pragyan Prasad Padmanav Reddy Monalisa Patro Santosh Kumar Kunal Kumar Siba Prasad Padhi M. Naresh Sudhansu Sekhar Gouda Ananda Kishor Mishra Chetan Kumar Shrivastav Syed Ramijul Bari Swastik Das Manish Kumar Nayak Rahul Kumar Singh Abhishek Manish Kumar Gupta Mani Kant Ojha Akhila Badatya

Kolkata Jamshedpur Baroda Chennai Chennai Chennai Chennai Chennai Mumbai Baroda Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar) Kolkata (Bhubaneswar)

REPORT ON MES-SDI SCHEME

REPORT ON MES-SDI SCHEME OF DGE&T, GOVT. OF INDIA As an Assessing Body under DGE&T, Govt. of India, IIW-India MAB during the period October to December 2011, received Assessment advises from various RDATs are as follows:

Sl. No.

Region

No. of advise

Course Name

Total Candidates

1

RDAT-Chennai

3

Basic Welding Gas / Basic Welding Arc

110

2

RDAT-Faridabad

8

Basic Welding Gas / Basic Welding Arc / Basic Fitting Work

230

3

RDAT-Hyderabad

6

Basic Welding Gas / Basic Welding Arc / Basic Fitting Work

175

4

RDAT-Kanpur

1

Basic Welding Gas / Basic Fitting Work

55

5

RDAT-Kolkata

5

Basic Welding Gas / Basic Welding Arc / Basic Fitting Work / Gas Cutting

130

6

RDAT-Mumbai

8

Basic Welding Gas / Basic Welding Arc / Basic Fitting Work

234 934

Out of 934 assessment advise received for various courses under fabrication sector, 781 candidates were assessed with 153 candidates remain absent. Out of these 781 candidates, 765 passed and 16 candidates failed. Report on NWTCS programme (National Welders' Training and Certification Scheme) During the period October to December, 2011 altogether 63 candidates had been certified by our Authorised Examiners at the following ATIs.

Sl. No.

Module

Level

Name of the ATI

1.

MMAW

Standard (Radiographic)

Punj Lloyd, Banmore, MP

31

MMAW

Standard (Radiographic)

Technocon Trg. Inst., Rajarhat, W.B.

10

GTAW

Standard

WELDTECH (Rishi Laser), Vadodara, Gujarat

12

GTAW

Standard

Zanders Skill Dev. Centre, Mohali, Punjab

5

GMAW

Standard

Zanders Skill Dev. Centre, Mohali, Punjab

5

TOTAL

63

2

3

Total Candidates

Under IIW-India's National Welders Training and Certification programme, during October to December 2011, 3-new Institutes had applied us for becoming IIW-India's Approved Training Institute for conducting NWTCS programme. They are 1) Deshpande Inst. Of Vocational Training, Karnataka 2) The Indian Steel & Wire Products Ltd., Jamshedpur 3) J. K. Centre for Technician's Training, Kanpur

27

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

THE INDIAN INSTITUTE OF WELDING (A Member Society of The International Institute of Welding) Head Quarter & Regd. Office Address: “MAYUR APARTMENTS”, Flat No. 4 B/ N, 3A, Dr. U. N. Brahmachari Streey, Kolkata - 700 017, INDIA Phone: 91 33 2281 3208 | Telefax: 91 33 2287 1350 E-mail: [email protected] | Website: http://www.iiwindia.com

AM - IIW Examinations : Summer Session, 2012 From June 11 to 14

SCHEDULE Forenoon 10:00 A.M. - 1:00 P.M.

Date / Day

Afternoon 2:30 P.M. - 5:30 P.M

11.06.2012 (Monday)

1. AME - 01 : Elementary Mathematics 2. AME - 14 : Heat and Mass Transfer 3. AME - 19 : Testing and Quality Assurance

1. AME - 02 : Physics 2. AME - 15 : Welding and Allied Processes - I 3. AME - 21 : Welding Applications

12.06.2012 (Tuesday)

1. AME - 04 : General English 2. AME - 08 : Electrical Engineering and Electronics 3. AME - 17 : Computation Methods and Computer Programming

1. AME - 06 : Industrial Sociology 2. AME - 09 : Material Science 3. AME - 18 : Weldment Design and Weld Procedure

13.06.2012 (Wednesday)

1. AME - 07 : Strength of Materials 2. AME - 11 : Engineering Drawing 3. AME - 23 : Welding Equipment and Consumables

1. AME - 05 : Applied Mechanics 2. AME - 13 : Welding Metallurgy - I 3. AME - 16 : Engineering Economics

1. AME - 03 : Chemistry 2. AME - 12 : Engineering Mathematics 3. AME - 20 : Welding Metallurgy - II

1. AME - 10 : Production Engineering 2. AME - 22 : Welding and Allied Processes - II 3. AME - 24 : Advanced Welding Technology

14.02.2012 (Thursday)

Last date for Receipt of Enrolment Forms : May 12, 2012

AM - IIW Examinations fees w.e.f. 01.06.2011 Sl. No

Type of Fee

(Rs.)

1.

Enrolment Fee

400.00

2.

Examination Fee per subject

350.00

3.

Examination Fee for Part ‘D’

1,500.00

WELDING - For Nation Biulding 28

AM - IIW

THE INDIAN INSTITUTE OF WELDING (A Member Society of The International Institute of Welding) Head Quarter & Regd. Office Address: “MAYUR APARTMENTS”, Flat No. 4 B/ N, 3A, Dr. U. N. Brahmachari Streey, Kolkata - 700 017, INDIA Phone: 91 33 2281 3208 | Telefax: 91 33 2287 1350 E-mail: [email protected] | Website: http://www.iiwindia.com

ANNOUNCEMENT Winter 2011 AM-IIW Examination will be held during June 11 to 14, 2012 (Monday to Thursday) at different Centres where I.I.W. Branches are located subject to the availability of candidates. The examination schedule and other related information will be sent to all the enrolled candidates individually as well as to the Branches for information. The last date for submission of the Registration Form and Enrolment Form for appearing at the examination, which will be available from the Prospectus, is May 12, 2012. Details of rules, regulations, subjects, course content etc are available in the Prospectus, which can be obtained from the IIW Head Office on payment of Rs.150/- by a Demand Draft favouring “The Indian Institute of Welding” payable at Kolkata. Bound copies of question papers of two previously held examinations at a price of Rs.225/- by Demand Draft are also available from the Head Office. EXEMPTION AVAILABLE IN THE REVISED SYSTEM OF COURSE QUALIFICATION

SUBJECTS EXEMPTED

10+2: with Maths, Physics, Chemistry

NIL

Diploma in Engineering

AME – 1, AME – 2, AME – 3, AME – 5*, AME – 7*, AME – 8*, AME – 11*

Bachelor of Science (B.Sc)

AME – 1, AME – 2, AME – 3

Degree in Engineering or equivalent

AME – 1 to AME – 6, *Also AME – 7, 8, 9, 10, 11, 12, 16, 17

NOTE: * Provided the subject has been successfully completed during the Qualifying Examination (Column 1). Exemption has to be claimed. In all claims, mark sheets must be produced to get exemption at the time of registration and exemption would be given only, if all documents, to the satisfaction of the examination committee are received. Prof. Joshi M. Das Controller of Examination SUBJECTS (REVISED SYLLABUS) PART A

PART B

PART C

AME-1 : Elementary Mathematics

AME-7 : Strength of Materials

AME-16 : Engineering Economics

AME-2 : Physics

AME-8 : Electrical Engineering & Electronics

AME-17 : Computation Methods & Computer Programming

AME-3 : Chemistry

AME-9 : Material Science

AME-18 : Weldment Design & Weld Procedure

AME-4 : General English

AME-10 : Production Engineering

AME-19 : Testing & Quality Assurance

AME-5 : Applied Mechanics

AME-11 : Engineering Drawing

AME-20 : Welding Metallurgy-II

AME-6 : Industrial Sociology

AME-12 : Engineering Mathematics

AME-21 : Welding Applications

AME-13 : Welding Metallurgy-I

AME-22 : Welding & Allied Processes-II

AME-14 : Heat & Mass Transfer

AME-23 : Welding Equipment & Consumables

AME-15 : Welding & Allied Processes-I

AME-24 : Advanced Welding Technology

N. B. : Last Date for Enrolment : May 12, 2012.

WELDING - For Nation Biulding 29

INDIAN WELDING JOURNAL Volume 45 No.1 January 2012

ANB – India News Transition Route for IWCP (IWE/IWT/IWS/IWP) Reopens: IAB authorized period for qualification of International Welding Coordination Personnel (IWCP) through the 'Transition Route' had initially ended on 31st December 2010. However, during the IAB meeting at Chennai in July 2011 the same was extended up to 31st January 2012. We are informed that the IAB, during the meeting at Paris in January 2012 has given further extension for International Welding Coordination Personnel till 31st July 2012. However, it must be noted by all concerned that the qualification criteria remains frozen as on 31st December 2010. That means all qualifications and experience prescribed must have been obtained by 31st December 2010. During the period from November 2011 - January 2012, there were a total of 5 refresher courses held at Kolkata (2 nos.), Baroda, Chennai and Delhi. A total of 60 candidates have appeared in the course.

International Welding Inspection Personnel (Basic / Standard / Comprehensive) courses by the Transition Route: The above course aims at integrating knowledge in Welding Technology and Welding Inspection and Organisations / Candidates engaged in Welding Inspection activity will find it extremely useful for their skill development and acceptance by various authorities. So, interested organizations / candidates may find it useful to visit our website www.iiwindia.com or write to us at [email protected]

Standard and Alternative Route for obtaining IWE / IWT qualifications: Standard Route: IWE / IWT candidates can presently avail this route at our Approved Training Body (ATB) M/s. Corner Stone Academy as per the access conditions. Qualified candidates without any experience subject to fulfilment of all conditions may enroll. At present the second batch of candidates for IWE / IWT diploma are in the process of completion of their stipulated course curriculum in preparation for appearing in the final examinations. . Alternate Route: This route is extremely suitable for candidates who fulfill the access conditions for the Standard Route and also have the minimum 4 years prescribed experience in the welding industry to avoid attending lessons in an ATB and appear for the final examinations. A few candidates have already applied to qualify under this route and are waiting to appear in the final examinations.

Welder Certification Activity: Encouraging progress is made in the above activity. TELCON along with their vendors has entrusted ANB - India with conducting certification tests for all their own and vendors welders in multiple units spread all over India. ANB - India has also undertaken welder's certification, preparation of WPS, WPQR for many organizations that follow ISO, EN and ASME Sec. IX standards. The recent formation of ANBCC for certification of companies under ISO 3834 has opened up new area for certification of welders and the emerging market is being fully exploited. All interested organizations / candidates are requested to visit our website under International section www.iiwindia.com or write to [email protected] to get the details of the qualification required, fees and the course calendar. 30

GUIDELINES FOR AUTHORS

GUIDELINES FOR AUTHORS FOR SUBMISSION OF PAPERS TO THE INDIAN WELDING JOURNAL INTRODUCTION

Margins and Spacing

The Indian Welding Journal (IWJ) is the official journal of

The top, bottom, left, and right margins should be kept

the Indian Institute of Welding (IIW-India), and it is

one inch each, with justified format. Spacing should

published four times a year. Papers are invited in the

adhere to the following format:

areas of welding and allied processes for publication in

The body text of the paper should be single-spaced

l

the IWJ as per the following categories;

and fully justified in 11-point Arial font. Leave one line

a) Original papers

space between paragraphs, but do not indent the first line of a new paragraph. Page numbers should be

b) Conference papers (For journal special issues, etc.)

centered at the bottom, and the first page should be

c) Critical assessments / Reviews

numbered.

d) Case studies / Application areas

Insert a line space after the final paragraph in a

l

section. TITLE PAGE

First level heading should be consequently numbered

l

The title page should include:

like 1., 2., etc., left justified, all caps and bold. Insert one line space before and after a first level heading.

The name(s) of the author(s)

l

Second level heading should be numbered

l

A concise and informative title

l

consequently like 1.1., 1.2., 2.1., 2.2., etc., left

The affiliation(s) and address(es) of the authors

l

justified, with running letter and bold, with one line

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For further information /clarification please

S. and Bhattacharya A. (2009);

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34

ESAB INDIA AWARD

Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor Girish Kumar Padhy1, V. Ramasubbu1, N. Murugesan2, C. Remash2 and S.K. Albert* 1 Material Technology Division, 2Material Chemistry Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603102, Tamilnadu, India.

ABSTRACT Diffusible hydrogen (HD) measurement in steel welding consumables having cellulose, rutile and basic coating has been carried out using a Proton Exchange Membrane Based Hydrogen Sensor (PEMHS). The sensor is an electrochemical fuel cell based device which uses Nafion@117 as proton exchange membrane electrolyte. This can detect hydrogen in an Ar+H2 mixture with detectable limit of 1 ppm. Further, HD measurements have also been carried out on basic coated electrodes of modified 9Cr-1Mo steel, with very low levels of HD content. Results obtained have been compared with those obtained from HD measurement using mercury manometer as per standard ISO 3690. One to one correlation has been obtained between these two different methods of measurements. This sensor has shown good sensitivity, accuracy and precision hence is reliable for HD measurement. In addition to the above measurement, this method was used to study hydrogen evolution from the weldments as a function of time. The paper presents and discusses the principles of HD measurement using this sensor, its applications for HD measurements in weldment, the results obtained, its application to study the hydrogen evolution from weldment as a function of time and the possibility of using this sensor for measurement of hydrogen evolved from the weld specimens at high temperatures. Keywords: Diffusible Hydrogen, Nafion Hydrogen Sensor, Hot Extraction, Hydrogen Diffusivity

1.0 INTRODUCTION Hydrogen in the weldments of carbon and alloyed steels when accompanied with a crack susceptible microstructure and tensile residual stress in the weldment causes Hydrogen Assisted Cracking (HAC) in the weld metal and in the heat affected zone (HAZ). As these cracks are not acceptable in weldments, formation of these cracks should be prevented. For predicting the susceptibility of weldment to HAC, amount of diffusible hydrogen (HD) content in steel

weldment is used extensively (Yurioka

metal causes dissolution of large

and Suzuki, 1990). Though many

amount of hydrogen atoms present in

sources

the arc atmosphere in the weld pool

such as

shielding gas,

oil/grease, hydrocarbons on the surface

whereas oxygen atoms form oxides

to be welded and moisture in the

which become parts of the slag formed

surrounding atmosphere may contri-

during welding. In general, solubility of

bute to hydrogen in welds, the chief

hydrogen in ferritic steel is less than 2

source is the chemically bonded water in

ppm by weight at STP. However, the

the flux coated on the welding electrode

rapid cooling rate (80-150K/second) of

(IIW Doc.II-805-85, 1985) which disso-

the deposited metal during welding

ciate into hydrogen and oxygen atoms in

does not allow hydrogen to equilibrate

the arc during welding. Very high

with the deposited metal and results in

temperature (~1600°C) of the molten

supersaturation of hydrogen in the

* Corresponding author E-mail : [email protected]

35

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

deposited metal, which starts diffusing

mercury (ANSI/AWS A4.3-86, DIN 8572,

attributed to the fact that hydrogen is

into the HAZ or out of the weld during

ISO 3690, IS-11802-1986, JIS Z3118-

partially soluble in glycerin. Many other

solidification and subsequent cooling.

1986) and gas chromatography (ANSI/

techniques such as determination of HD

During this diffusion, most of the

AWS A4.3-86, ISO 3690, JIS Z3118-

content using mass spectrometer

hydrogen is retained at various defects

1986, Ohtsubo et al., 1985, Quintana

[(Noble, 1985), (Pressouyre et al.,

called traps which are classified (Hirth,

and Dennecker, 1986) methods. A good

1988)], low frequency impedance based

1980) as reversible traps (e.g. grain

agreement between the results has

non contact diffusible hydrogen sensor

boundaries, lath boundaries, dis-

been reported with measurements

(Lasseigne, 2008), and computer aided

locations etc.) and irreversible traps

carried out using mercury and gas

determination of diffusible hydrogen

(e.g. vacancy, particle matrix, inclusions

chromatography methods (De Abreu et

(Karkhin and Levchenko, 2007) are also

etc.) in the weld and in the HAZ. At room

al., 1995). However, these methods are

reported.

temperature, irreversible traps have

not free from drawbacks. Limitations in

higher binding energies and release of

using the mercury method are the

hydrogen from these traps is difficult.

health and safety issues associated in

However, reversible traps, owing to their

the handling of mercury, the long

lower binding energies [(Iino, 1987),

durations of hydrogen collection (72

(Iino, 1998)] release hydrogen in

hours or longer after welding (Ravi and

subsequent times which is able to

Honavar, 1987)), non-applicability of

diffuse further. Hence, only a part of the

this method at higher temperature for

total trapped hydrogen tends to diffuse

hydrogen collection which would reduce

at or near room temperature (25-45°C)

the time of hydrogen collection. Also,

which is referred as diffusible hydrogen

this method provides no scope for

(HD). Cracking is caused by interaction of

studies such as the evolution of

HD with defects, which are locations of

hydrogen from the weld as a function of

stress concentration in the welds.

time from a single specimen, the

Hence, HD content in the weld metal

evolution of hydrogen at higher tempe-

shall be controlled and estimation of

ratures etc. For welding consumable

hydrogen by a suitable technique is the

manufacturers the test duration of 72

first step in the efforts to avoid cracking.

hours is quite long; but time cannot be

An understanding of the HD content is

shortened with this method as the

also useful to predict the minimum

measurement cannot be carried out at

preheat temperature to be employed

high temperatures. Gas chromato-

during welding of steels to avoid

graphy method permits heating of

cracking [(Suzuki and Terasaki, 1986),

samples up to a maximum of 400°C

(Ito and Bessyo, 1968)]. As one of the

reducing the test duration to 20-30

major sources of hydrogen is the

minutes. However, the equipment is

welding

costly. Another method, involved in

consumables,

they

are

classified based on the HD content in the

collection of HD over glycerin (JIS Z3113-

weld metal produced by them.

1975) is in limited use [(Quintana, 1984), (Siewert, 1986)] because it

Measurement of HD content from a weld

lacked accuracy and furnished lower HD

is carried out by measuring hydrogen

contents than those obtained using gas

evolved from the weld at a fixed

chromatography and mercury methods

temperature for a given duration.

(Kotecki and La Fave, 1985). The lower

Standards such as ISO, AWS, DIN, BIS and IS have recommended procedures for HD measurements which include

H D contents obtained using the collection of hydrogen over glycerin is

36

HD measurement can also be carried out using chemical sensors available for detection

and

measurement

of

hydrogen in gas mixtures. These sensors include pellistor sensors [(Krawczyk, 2003), (http://www. e2v.com)], semiconductor sensors (Lin et al., 2003), thermal conductivity based devices, electrochemical sensors etc. Pellistor sensors require atmospheres containing oxygen/air in explosive range hence are not suitable for HD measurement. Semiconductor sensors are based on conductivity changes caused by the chemisorbed oxygen due to hydrogen exposure. Hence oxygen is required along with hydrogen. Thermal conductivity based devices are bulky and not suitable for field applications. Electrochemical

sensors

for

hydrogen

measurement include both potentiometric [(Miura, 1983), (Miura and Yamazoe 1988)] and amperometric [(Miura,

1984),

(Miura,

1989)].

Potentiometric sensors are suitable at low concentrations but are nonlinear in response. Amperometric sensors are linear in response and use of an amperometric sensor, H 2 /Pt//PVA//Pt/O2, (comprising of a proton-conducting polymer, Polyvinyl Alcohol (PVA) as its electrolyte) for HD measurement has been reported [(Albert et al., 1997), (Albert, Ph.D Thesis, 1996)]. The results obtained from the sensor agreed well

Girish Kumar Padhy - Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

Table 1: Chemical compositions in of mild steel and modified 9Cr-1Mo in Wt%

with that of the standard Gas Chromatography method. However, it was seen that the PVA membrane

Elements

Mild steel

Modified 9Cr-1Mo

modest comparison of all the available

C

0.205

0.114

solid and liquid electrolytes showed that

Cr

-

8.838

Mo

-

0.860

(>60,000 hours), high chemical stability

Mn

0.551

0.403

and high ionic conductivity to opt for

Si

0.061

0.309

P

0.039

0.014

(Viswanathan and Helen, 2007)]. Nafion

Sr

0.047

based electrochemical cells, H2/Pt//

Nb

-

0.080

V

-

0.027

[(Sakthivel and Weppner, 2006),

Cu

0.321

(Velayuthamet al., 2004), (Ramesh et

Fe

Balance

suffers from poor long term stability. A

Nafion is the best available polymer membrane because of its high longevity

PEM fuel cell applications [(Smitha et al., 2005), (Neburchilov et al., 2005),

Nafion//Pt/O2, has been used for measurement of hydrogen in Argon

Balance

al., 2008)]. The present study is involved in the application of this Nafion based electrochemical sensor for HD measurement in welding consumables.

2.0

EXPERIMENTAL

2.1

Materials used in the study

2.1.1 Test specimen For HD measurement, the specimen was All dimensions are in mm

prepared as per standard ISO 3690. A

Fig. 1 : Schematic of the Specimen assembly

triplicate set of specimen assembly comprising of a specimen of dimension 30 mm x 15 mm x 10 mm, a run-on and a

assembly to the fixture. Beads were

run-off piece each of dimension 44 mm x

deposited with welding electrodes with

closed using a plug and the leak

15 mm x 10 mm were prepared from

different hydrogen levels on the

tightness of the plug is ensured with the

valves. The chamber can be opened or

mild steel and modified 9Cr-1Mo steel.

specimen assembly by manual metal arc

help of an O-ring. The chamber was

The chemical composition of steels used

welding (MMAW) process. A schematic

subjected to helium leak testing and it

is given in Table 1. The surfaces of the

diagram of the specimen assembly is

was found that the leak rate is less than

triplicate set were finished at right

shown in Fig. 1.

10-9 sccm. Fig. 2 shows the schematic of

angles to ensure good contact between the adjacent pieces. The sample was weighed to the nearest 0.01g prior to

2.1.2

Hydrogen

Collection

Chamber

the chamber along with plug. The volume of the chamber is measured by filling it with distilled water and draining

welding. The specimen assembly was

A hydrogen collection chamber (Lundin

the water completely into a measuring

clamped in a copper fixture. The

et al., 1986) was used to collect HD from

jar.

dimensions of the fixture was such that

the weld specimen. The chamber is

during welding, the heat is conducted

made of stainless steel and has an inlet

away immediately from the test

and an outlet connected to needle

37

2.1.3 Gas sampling valve An 8-port gas sampling valve with a

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

sampling loop of known volume was used for sampling the gas from the hydrogen collection chamber for analysis. The sampling valve operates in two modes as shown in Fig. 3. Mode 1 is the sampling mode and Mode 2 is injection mode. In mode 1, as shown in Fig. 3, the inlet of the sampling loop is connected to the specimen chamber (sample gas) through port 7 and port 8 and the outlet is open to atmosphere through port 4 and port 3. In this mode only the carrier gas which enters

O-Ring Dia 40

through port 5, is passed onto the detector/sensor through port 2 and port 1. In Mode 2, as shown in Fig. 4, the inlet of the sampling loop is connected to the carrier gas line through ports 5 and port 4 and outlet to the detector/sensor through port 8 and port 1. In this process, the sample gas collected in the loop while operating in Mode 1 is carried away to the sensor by the carrier gas. While operating in this mode specimen chamber is kept closed so that gas inside the specimen chamber is conserved. For analysis of the gas, initially the valve was operated at mode 1. The gas from the specimen chamber, which was filled at a higher pressure than the ambient pressure, was used to flush

Flow Control Valve

the sampling loop while the carrier gas was flowing into the sensor. At the end of flushing, the valve was switched over to mode 2 operation and the carrier gas flowed through the sampling loop to the sensor carrying the gas trapped in the loop along with it. The sensor gives a signal corresponding to concentration of hydrogen in the gas mixture. 2.1.4 Hydrogen Sensor The hydrogen sensor used is an electro-chemical cell which has

All dimensions are in mm

Nafion, a proton conducting polymer, as its electrolyte. The

Fig. 2 : Schematic diagram of Hydrogen Collection Chamber

polymer is cast as a film, coated with platinum black on the sensing and counter electrode side. The sensing side of the coated polymer is exposed to the hydrogen argon gas mixture while the counter side is exposed to air. Thus the sensor consists of hydrogen exposed inner platinum film and air exposed outer platinum film with the conducting polymer Nafion, sandwiched between them acts as a fuel cell. A mechanical barrier limits the supply of hydrogen at the sensing electrode. A schematic representation of the sensor with conducting leads is shown in Fig. 5. Hydrogen present in the Ar-H2 mixture gets chemisorbed at the sensing electrode and loses its electron to form H+ which permeates through the polymer to reach the counter electrode where it encounters oxide ion (O2-, which is produced by taking up the electrons lost by hydrogen and oxygen from the ambient) to form H2O.The

Fig. 3 : Valve in Mode 1 for sampling the diffusible hydrogen gas

reactions taking place at the anode and at the cathode of the

38

Girish Kumar Padhy - Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

beads of the above mentioned electrodes on mild steel specimen and bead of the low hydrogen electrode, P91M (with a composition modified from that of E9015-B9), on modified 9Cr-1Mo specimen. Table 2 give the electrode details

and

welding

parameters

employed for preparation of specimens for HD measurement. The specimen assembly for HD measurement was removed from the copper fixture immediately after welding, quenched in ice cold water followed by liquid nitrogen. The test specimen was separated from the run-on and run-off pieces within 4-6 seconds. Any flux remaining on the weld specimen was Fig. 4 : Valve in Mode 2 for injection of sampled gas onto the sensor

removed within 20 seconds and was stored in liquid nitrogen until its transfer

above electro-chemical cell are as

hydrogen in the hydrogen collection

into the hydrogen collection chamber for

follows:

chamber.

collection of HD.

At the anode

2.2 Diffusible Hydrogen

2.2.2 Collection and measurement

(Sensing side): H2 →2H+ + 2e-

Measurement

of diffusible hydrogen using the

At the cathode (Couneter

2.2.1 Preparation of specimen for

side): 2H+ + ½O2 + 2e- →H2O

the HD measurement

During the conduction of hydrogen ion

Five different classes of electrodes

weld specimen, it was cleaned with

through the polymer membrane, a short

which are known to have different levels

acetone to remove the ice/moisture,

circuit current is produced and a peak

of HD content were used for HD measure-

gently warmed to remove excess

corresponding to the short circuit

ment using the sensor. Prior to welding,

current was observed in the data

the specimen was degassed by holding

acquisition system which in turn is used

it at 650oC for 1 hour and the welding

to measure the concentration of

electrodes were baked as per the requirement given in Table 2. Weld specimens were prepared by depositing

sensor For the collection of HD evolved from the

acetone and was transferred into the collection chamber within one minute. The chamber along with the specimen was flushed and pressurized with argon gas to a known pressure higher than the ambient. After pressurizing, the weld specimen was held in the chamber for 72 hrs for collection of HD as a mixture of

Diffusion barrier

hydrogen in argon (Ar-H2 gas mixture). Volume of HD in the Ar-H2 gas mixture is

Pt (Sensing Electrode)

measured by the sensor as described below.

Nafion Pt (Reference Electrode)

Prior to the measurement of Volume of HD in the chamber, sensor was calibrated with different known concentrations of hydrogen in the Ar-H2 gas mixture of by injecting a fixed volume (this volume is

Fig. 5 : Schematic of Hydrogen Sensor

39

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

Table 2: Baking and Welding parameters of different electrodes

Electrodes

Baking conditions

Welding current (Amp)

Voltage (Volt)

E6010

Not Baked

110

25

E6013

125ºC/1h

110

27

E7016

250ºC/2h

110

28

E7018-1

250ºC/2h

110

27

P91M

300ºC/2h

90

28

further sizable hydrogen concentration in the Ar-H2 mixture was obtained for a subsequent time interval after 264 h of HD measurement. 2.2.4 Measurement of diffusible hydrogen at high temperature. For collection of HD at high temperature, a new chamber was designed (Fig. 6) which has heating arrangements inside it. Weld specimen was prepared as per the

standard procedure already

equal to the volume of the sampling loop

concentration in the gas mixture,

of the valve shown in Figs. 3 and 4) of

pressure of the gas inside the chamber,

described and for HD measurement it

the gas mixture onto the sensor with the

weight of the deposited metal, volume

was transferred into heater inside the

help of the 8-port valve. Concentrations

of HD content was estimated and was

chamber. The chamber along with the

of hydrogen in the gas mixture were

reported in ml/100g of the deposited

weld

varied

specimen

is

flushed

and

metal. For each set of specimens, five

pressurized with argon; then the

controllers. Signal/response of the

separate measurements were carried

specimen is heated to 400°C for 0.5h

sensor corresponding to each concen-

out and the average values were

and hydrogen diffused out from the

tration of hydrogen in the Ar-H2 gas

reported.

by

standard

mass

flow

mixture was recorded as a peak height of the peak is proportional to the concentration of hydrogen in the gas

specimen is collected inside the

2.2.3 Measurement of diffusible hydrogen with respect to time

chamber. It is cooled down to room temperature and the concentration of hydrogen is measured with the sensor.

mixture. After calibration, the inlet of

In addition to the standard 72 hour

sampling loop of the 8-port valve was

measurement, HD measurement from

connected to the chamber, the sampling

weld specimen was also carried out at

loop is flushed and filled with the gas in

different time intervals using the sensor.

Since the sensor method is a new

the chamber. Subsequently, by choosing

For feasibility of the measurements,

technique, all the HD measurements

the injection mode of the eight port

they were carried out at long time

carried out using this method were

valve, the gas mixture in the sampling

intervals after 72h. Apart from the

compared with similar measurements

loop was injected into the sensor. A

difference in the time duration of

using mercury method following

response

the

collection of HD, the procedures of

standard ISO 3690 procedure. The

concentration of hydrogen in the

specimen preparation and HD measure-

quenched and cleaned specimen was

chamber is recorded in the data

ment were the same as discussed in

acquisition system and compared with

sections 2.2.1 and 2.2.2. In this study,

the

the

HD was collected from a single weld

concentration of HD collected in the

specimen for time intervals of 0-24, 24-

obtain

chamber. As the specimen chamber is at

48, 48-72, 72-120, 120-192, 192-264 h

a higher pressure than the ambient, it

and was measured using the sensor.

was possible to repeat the measurement

After measuring the concentration of

at least thrice using the gas mixture

hydrogen evolved for a certain time

available in the chamber. After

interval, the chamber containing the

measuring HD concentration, the weld

same specimen was flushed and

specimen was taken out of the chamber,

pressurized again with argon to a known

cleaned, dried and weighed. From the

pressure and the measurement was

volume of the chamber, hydrogen

repeated for the next interval until no

40

the specimen inside was allowed for hydrogen evolution for 72 hours. Hydrogen evolved was collected in the burette of the Y-tube. This volume is subsequently converted to the volume at STP and knowing the mass of the specimen, HD content was normalized by the following relationship: HD =

-H 273 (273+T ( P760 (

(

to

transferred into the Y- tube filled with mercury. The Y- tube was evacuated and

(

c a l i b ra t i o n

to

100 L2 - L1

(

corresponding

2.2.5 Measurement of diffusible hydrogen by the mercury method

(V2 - V1) ml / 100g of weld deposit ..(1)

Girish Kumar Padhy - Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

Where, HD

= Diffusible hydrogen at STP (ml/100g)

T

= the room temperature (K)

P

= the barometric pressure (mm)

H

= (L2 - L1), the head of mercury

L1

= Height of mercury level in the

(mm) graduated limb after 72 hours (mm) L2

=Height of mercury level in the non-graduated limb after 72 hours (mm)

V1

= left over gas in the graduated capillary of the closed limb

Fig. 6 : Hydrogen collection chamber

before evacuation (ml) V2= the volume of hydrogen collected in the graduated limb after 72 hrs (ml)

3.0 RESULTS AND DISCUSSION 3.1 Diffusible Hydrogen content A typical response of the sensor for different concentrations of hydrogen in the Ar-H2 mixture is shown in Fig. 7. Fig. 8 shows the calibration of the sensor which presents variation in peak heights Fig. 7 : Response of the hydrogen sensor against the concentration of hydrogen

with

concentrations

of

hydrogen. The trend indicates a linear relationship of peak height with the concentration of hydrogen. Sensor was calibrated prior to each set of measurements. Results of the HD measurements for welding electrodes carried out using the Nafion sensor and mercury method are shown in Fig. 9. A good agreement for the results obtained both from the sensor and the mercury method for a wide range of electrodes and levels HD contents is obvious. In fact standard deviation is less for measurements

Fig. 8 Calibration curve for hydrogen sensor obtained using standard Ar-H 2 mixtures

41

made using the sensor than those made by mercury method. Further, in Fig. 10,

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

a plot of HD contents obtained using sensor method against HD contents obtained using mercury method for similar test sets was seen linearly related with R2 = 0.9999. A mathematical correlation of HD contents obtained for different test sets using both these methods show one to one correspondence between these two methods as given below : H Sensor Method = 0.99H Mercury Method -0.05 ...(2) Hence, the results prove that the Nafion based hydrogen sensor can be used for HD measurements in the weld joints Fig. 9 : Comparison of Mercury method and Sensor method

3.2 Accuracy of the Sensor Method by t-Test Following the recommendation of ISO 3690, t-Test has been carried out to check the accuracy of the hot extraction method as compared to mercury method. In this test, the means of HD contents of each electrode measured by the mercury method (primary method) and the mensor method (alternate method) are compared statistically by two-sided t-Test. The observed t value (testimated) is estimated from equation (3). The testimated for each electrode was compared with the tstatistical obtained from

Fig. 10 : Relationship between mercury and sensor methods

the t-table of statistics for the number of degrees of freedom, ? =9 (Where, ? = nP+nR-2) at 95% confidence level (i.e.,

xP =

the level of significance, ? = ±0.025 for two-sided t-test) for each electrode. The details are given in Table 3 t

estimated

=

(x

?

S

2

n

(Mercury) sR =

R R

+

S n

2 P

....... (3)

sp =

Where,

nR =

testimated = the probability of difference in means not due to chance xR =

Mean of the sensor method (Alternate)

nP=

± 0.025, 9

(at 95% confidence

Standard deviation of the rapid

From the Table 3, it is obvious that

method

testimated for all the set of measurements,

(Hot

extraction-

except one, fall within the interval of

Standard deviation of the primary method (Mercury)

P

tstatistical = t

level in two sided test)

PEMHS)

- x P)

R

Mean of the primary method

t statistical = ±2.262 (Obtained from statistical t-table (Beckwith et al., 2006). The lone deviation observed is for the

Sample size in the rapid

E9015-B3 electrode deposited on mild

method

Extraction-

steel base metal; it may be noted that

PEMHS)

(Hot

composition of the base metal (mild

Sample size in the primary

steel) and weld metal (9Cr-1Mo steel)

method (Mercury)

are vastly different and this could be the

42

Girish Kumar Padhy - Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

reason for large value of testimated. Results

mentioned above, the new sensor

of evolution of hydrogen per hour within

prove that probability that good

method was successfully employed to

the time intervals of HD collection and

correlation obtained for HD content

study evolution of hydrogen as a

plotted against time in Fig. 12 which

measured by the sensor method and

function of time. In this study, hydrogen

shows rate of hydrogen evolution

the mercury method for different

concentration in the chamber was

decreases exponentially with time. Also,

electrode is by chance is less that 5%. In

measured for different time intervals

in Fig. 13, the cumulative total of HD

other words, with more than 95%

from weldment of modified 9Cr-1Mo

contents collected after different time

confidence level, it can be said that the

electrode (modified E9015-B9) on mild

periods clarifies that hydrogen evolution

results obtained for HD measurement

steel base metal up to 264 hours. This

is maximum within the first 24 hours

using sensor method is as accurate and

class of electrode was chosen because it

then it decreases exponentially with

as reliable as the results obtained from

is an alloy steel electrode and in the as

time. However, it should be noted that

the standard mercury method. The

welded condition, the microstructure of

total HD measured after 72 h (1.85 ml/

differences in means are only due to

the weld metal is fully martensitic and

100 g) is lower than HD obtained for the

random errors and not due to any

diffusion coefficient for hydrogen in this

single measurement carried out after 72

systematic errors. Hence, sensor

class of steel at ambient temperature is

h (2.1 ml/100 g). This could be because,

method can be used to measure HD

two orders magnitude lower than that in

the first 72 h measurement was divided

measurement as an alternative to the

mild steel (Albert et al., 2003). It was

into three 24h measure-ments and were

standard mercury method. This method

observed that evolution of hydrogen

carried out using a single sample and in

is environment friendly and possibly

continued even after 264 hours. HD

between two successive measurements,

emerges as a rapid method for HD

contents measured at various intervals

few hours are lost for measurement (gas

measurement. Once developed into a

for modified E9015-B9 deposited on

from the specimen chamber is sampled

commercial product, it is expected to be

mild steel is shown in Fig. 11. The

at least thrice for each measurement),

much cheaper than the Gas Chromato-

exponentially decreasing pattern of

flushing the chamber and refilling with

graphy method, another rapid method

diffusible hydrogen content with respect

Ar gas. Hence, gas evolved during these

currently available for HD measurement.

to succeeding time intervals was not

periods is not collected. However, the

observed from this data because the

results are sufficient to demonstrate

time intervals of measurement were not

that rate of hydrogen evolution

3.3

Hydrogen evolution as

function of time

equal. Hence, the data in Fig. 11 has

decreases with time and hydrogen

As per one of the applications

been normalized by estimating the rate

evolution continues much beyond 72 h.

Table 3: Comparison of means of HD obtained from both the methods by t-test

Standard Deviation of HD content (ml/100g)

Average HD content (ml/100g) Base Metal + Electrodes

Mercury Method

t-Value

Sensor Method

Mercury Method

Mild Steel +E6010

18.28

18.58

0.412

0.871

-0.7444

Mild Steel +E6013

9.37

9.56

0.338

0.438

-0.8352

Mild Steel + E7018-1

5.68

5.81

0.214

0.248

-0.9488

Mild Steel + E7016

4.19

4.26

0.102

0.124

-0.9449

Mild Steel + E9015-B9

2.11

2.19

0.0311

0.0588

-2.8317

9Cr-1Mo + E9015-B9

2.19

2.26

0.0711

0.117

-1.1950

Sensor Method

testimated

tstatistical (From Table)

(tstatistical = t±0.025,9) ±2.262

43

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

3.4 Diffusible hydrogen measurement by the sensor at high temperatures Measurement of diffusible hydrogen was carried out at 400°C from the weldment prepared by depositing P91M welding electrodes on mild steel. Hydrogen from weld metal was collected in the chamber mentioned in section 2.2.4 and its concentration was measured with the sensor. The results of this measurement are given in Table 4. These results are found to be in good agreement with the results obtained by

Fig. 11 : Diffusible hydrogen measured at different intervals

the standard mercury method and with the results obtained with the sensor method at room temperature. Measurement of diffusible hydrogen in welding electrodes with various levels of hydrogen using the high temperature method is in progress.

4.0

CONCLUSIONS

1. The Nafion based hydrogen sensor has been successfully employed for measuring diffusible hydrogen content in the welding consumables. 2. Measurements were carried out for five different classes of welding consumables

with

Fig. 12 : Rate of hydrogen evolution with time

d i ffu s i b l e

hydrogen content in the range of 218 ml/100g of weld metal using the sensor and the standard mercury method. Results obtained correlate well with those obtained by mercury method. 3.

Statistical analysis of the results, as recommended by ISO 3690 confirms that confidence level on the accuracy of the measurement of diffusible hydrogen using the sensor is better than 95%. Hence, this method can be used as an alternate method for diffusible hydrogen measurement from the welding consumables.

Fig. 13 : Cumulative diffusible hydrogen Content

44

Girish Kumar Padhy - Diffusible Hydrogen Measurement in Steel Welds using an Electrochemical Hydrogen Sensor

Table 4 : Diffusible Hydrogen Measurements by Hot Extraction

4. One of the possible application of the new method, hydrogen evolution from the weld as a function of time

HD measured by sensor method at 400°C (ml/100g)

Base Metal + Electrodes

was also demonstrated by conducting measurement on a weld of modified 9Cr-1Mo steel electrode

Mild Steel +

deposited on mild steel. It is shown

P91M (Baked)

that rate of hydrogen evolution decreases exponentially with time and it continues much beyond 72 h, Average

the standard time of diffusible

HD measured by sensor method at room temperature (ml/100g)

HD measured by Mercury method (ml/100g)

2.43

2.14

2.18

2.51

2.14

2.23

2.39

2.10

2.24

2.44

2.13

2.22

hydrogen measurement at ambient temperatures.

Measurements, Fifth Edition, Pearson

5. A new method for measurement of diffusible

hydrogen

at

high

temperature using the sensor with considerable reduction of the collection time of hydrogen from the weld is demonstrated.

Education.

deposited weld metal from covered

De Abreu, L. C., Modenesi, P. J. and Villani-Marques, P. (1995); Comparative study of methods for determining the

Ito, Y. and Bessyo, K. (1968); Cracking parameter of high strength steels

diffusible hydrogen in weld metal, Deutsches Institut fur Normurg e.V.,

varthini, N. and Gill, T.P.S. (2003);

Berlin (1981).

assisted

cracking

and

diffusible

hydrogen content in Cr-Mo steel welds, Sâdhanâ 28(3-4), pp. 383-393. Albert, S. K., Ramesh, C., Murugesan, N., Gill, T. P. S., Periaswami, G. and Kulkarni, S. D. (1997); A New Method to Measure Diffusible Hydrogen Content in

Hirth, J. P. (1980); Effects of hydrogen

Japanese Standards Association, 1986. JIS Z3113-1975: Method for measurement of hydrogen evolved from

http://www.e2v.com/assets/media/files /sensors_datasheets/Pellistors/pellistor

deposited metal. Karkhin, V. A. and Levchenko, A. M.

_an1.pdf (Web Source: Pellistor Sensor

(2007); Computer-aided determination

Technology and Applications)

of diffusible hydrogen in deposited weld

trap binding enthalpy I, Metall. Trans. A,

Weld. J., 76(7), pp. 251s-255s.

18A (9), pp.1559-1564.

Albert, S. K., Studies on some aspects of

Iino, M. (1998); Evaluation of hydrogen

weldability of Cr-Mo Steels, Ph.D Thesis,

trap binding enthalpy II, Metall. Trans.

IIT-Bombay.

A, 29A (9), pp. 1017-1021.

ANSI/AWS A4.3 - 93: Standard methods

IIW

for determination of the diffusible

measurement of weld hydrogen levels,

hydrogen content of martensitic, bainitic

Welding in the World, 1985, 23 (3/4),

and ferritic steel weld metal produced by

pp. 50-62.

Beckwith, T. G., Maragoni, R.D.,

JIS Z3118-1986: Method of measure-

Metall. Trans. A, 11(6), pp.861-890.

Electrolyte Based Hydrogen Sensor,

Lienhard, J. H., (2006); Mechanical

IIW Doc.IX-576-68.

on the properties of iron and steel,

Iino, M. (1987); Evaluation of hydrogen

Miami, Florida (1986).

related to Heat-Affected-Zone cracking,

ment of hydrogen evolved from steel,

Steel Weldments Using a Polymer

arc welding, American Welding Society,

steels, Bureau of Indian standards, New Delhi.

Welding International, 9(1), pp. 26-31.

Albert, S. K., Ramasubbu, V., ParvathaInfluence of alloying on Hydrogen

electrodes for welding mild and low alloy

diffusible hydrogen content in welds

DIN 8572 Part 1: Determination of

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AWS A5 Committee studies of weld metal diffusible hydrogen, Weld. J., 64 (3): 31-37. Krawczyk, M. and Namiesnik, J. (2003); Application of a catalytic combustion sensor (Pellistor) for the monitoring of the explosiveness of a hydrogen-air mixture in the upper explosive limit

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content in arc weld metal, II-E-586-10.

Management in Chemistry, 2003, 25(5),

IS-11802-1986: Methods of determ-

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INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

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Diffusible Hydrogen Sensors for Steel Weldments,

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596 Miura, N., and Yamazoe, N. (1988) Development of a solid-state gas sensor using proton conductor operative at room temperature, Chemical Sensor

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Elsevier, Amsterdam, pp 123-139

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Ramesh,

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(2008);

Chem. Lett., 17(2), pp. 1905-1908

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Hydrogen In Air At Room Temperature,

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Ve l a y u t h a m ,

Proton

To

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Murugesan, N., Manivannan, V.,

Ramesh, C., Murugesan, N., Krishnaiah,

Sensitive

Control, ASTM STP 962, American

ttlement: Prevention and control and

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Control, L. Raymond, ASTM STP 962,

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Measurement during Weld Cladding,

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Nafion-based Solid

Is nafion, the only choice?, Bulletin of the Catalysis Society of India, 6, pp. 5066. Yurioka, N. and Suzuki, H. (1990);

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low alloy steel weldments, Int. Mat. Rev., 35(4), pp. 217-249.

46

I. T. MIRCHANDANI MEMORIAL RESEARCH AWARD

Dissimilar Metal Gas Tungsten Arc Weldments of Maraging Steel and Medium Alloy Medium Carbon Steel – Effect of Post-weld Heat Treatments P. Venkata Ramana1 and G. Madhusudhan Reddy2 1 2

Mahatma Gandhi Institute of Technology, Gandipet, Hyderabad – 500 075 Defence Metallurgical Research Laboratory, Kanchanbagh, Hyderabad – 500 058

ABSTRACT Maraging steel and medium alloy medium carbon steels exhibit their best mechanical properties such as tensile strength and toughness in their respective heat treatment conditions. Gas tungsten arc welding of maraging steel and medium alloy medium carbon steel was carried out taking both the steels in soft annealed condition. Later the weldments were subjected independently to two post-weld heat treatments, one corresponding to the maraging steel i.e. solutionising at 815oC/1 hr/air cooled & aging at 480oC/3 hrs/air cooled, and the other corresponding to medium alloy medium carbon steel i.e. quenching at 925oC/35 min/air cooled & tempering at 295oC/45 min/air cooled. The effect of post-weld heat treatments on the microstructure and mechanical properties such as hardness, tensile strength and impact toughness of the dissimilar metal welds of maraging steel and medium alloy medium carbon steel was investigated. The influence of filler materials was also studied by employing maraging steel and medium alloy medium carbon steel fillers. Maraging steel welds responded to the solutionising and aging treatment whereas the medium alloy medium carbon steel welds responded to quenching and tempering. Lowering of the hardness was observed at the interaction of maraging steel and medium alloy medium carbon steel due to the diffusion of manganese. Medium alloy medium carbon steel filler welds showed good strength and toughness properties. Key words : Maraging steel, Medium alloy medium carbon steel, Gas tungsten arc welding and Post-weld heat treatment.

1.0

INTRODUCTION

Structural steels with very high strength levels are often referred to as ultrahighstrength steels. These steels with ultrahigh strength coupled with fracture toughness, in order to meet the requirement of minimum weight while ensuring high reliability, are widely used

defence applications. For many of the

iron-nickel alloys that gain strength

advanced applications, for both the

through age hardening of low carbon

technical and economic reasons,

martensite resulting in the precipitation

dissimilar combinations of ultrahigh

of strengthening intermetallic phases in

strength steels are necessary. For such

the martensitic matrix [5-13]. Medium

applications, maraging steel and

alloy medium carbon steels are ultrahigh

medium alloy medium carbon steels are

strength steels with reasonable ductility,

now being used.

considered to be inexpensive and

in light weight high-performance

Maraging steels are a class of very low

structural applications [1-4]. Because of

carbon high alloy martensitic steels with

these properties these steels are

ultra-high strength combined with good

extensively used in aerospace and

fracture toughness. These steels are

* Corresponding author E-mail : [email protected]

45

attractive substitute for maraging steel [4]. These steels with good weldability are important candidate materials for critical applications such as rocket motor

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

cases, submarine hulls etc [4, 14].

the one of the heat treatments. The aim

thick sheets of 18% Ni (250 grade)

Though these steels are extensively

of the present study is to investigate the

maraging steel and medium alloy

used individually data are scarce about

influence of post-weld heat treatment

medium carbon steel. Gas tungsten arc

the dissimilar combination.

and influence of filler materials on the

welding of maraging steel and medium

Dissimilar materials' welding is qualitatively different from that of similar materials welding because of many differences in physical, chemical and mechanical properties of parent materials [15-20]. These differences also complicate the selection of filler metals compatible to both base metals.

mechanical

alloy medium carbon steel was carried

properties such as hardness, tensile

microstructure

and

out taking both the steels in soft

strength and impact toughness of

annealed condition. Later the weld-

dissimilar metal welds of maraging steel

ments were subjected independently to

and medium alloy medium carbon steel.

two post-weld heat treatments, one

The limited availability of the data on the

corresponding to the maraging steel i.e.

dissimilar welds of these steels makes

solutionising at 815OC/1 hr/air cooled &

this study significant.

aging at 480OC/3 hrs/air cooled, and the other corresponding to medium alloy

Generally for better properties of the dissimilar weld, filler metal selection is

medium carbon steel i.e. austenising at 2.0 EXPERIMENTAL PROCEDURE

925OC/35 min/air cooled & tempering at

dissimilar metals [21-24]. One of the

2.1 Parent materials, welding

295OC/45 min/air cooled. The details of

widely used fabrication process for

process and post-weld heat

weld coupon preparation and test plate

ultrahigh strength steels is fusion

treatments

welding in general and gas tungsten arc

The materials investigated are 5.2 mm

often compromised between the two

welding

p ro c e s s

in

assembly are shown in Fig.1. The para-

p a r t i c u l a r.

meters used for welding are given in Table 1. Two fillers namely maraging

Consistency in weld quality, process control, economy and weld joint efficiencies exceeding 90% are the features of gas tungsten arc welding with respect to these steels. Mechanical properties such as tensile strength and impact toughness play an important role in the design of components. The adoption of dissimilarmetal combination provides possibilities for the flexible design of the component by using each material efficiently i.e., benefitting from the specific properties Fig. 1 : Weld coupon design and test place assembly

of each material to meet functional requirements.

Table 1 : Gas tungsten arc welding parameters

Maraging steel and medium alloy

Welding current

130 A

medium carbon steels, used in this

Welding speed

60mm/min

Electrode polarity

DCSP

ultrahigh strength after respective heat

Arc voltage

18-20 V

treatments. When used in similar metal

Filler wire diameter

1.6 mm

combination the materials will be

Electrode

2% Thoriated tungsten

subjected to their respective heat

No .of passes

2

Shielding gas

Argon, flow rate 35 CFH

Preheat

None

study, are generally supplied in soft condition. These steels attain their

treatment schedules. But, when it comes to dissimilar combination it becomes important to choose between

46

P. Venkata Ramana - Dissimilar Metal Gas Tungsten Arc Weldments of........................ Effect of Post-weld Heat Treatments

Table 2 : Composition of parent materials and filler materials

Element (wt %) Material C

Ni

Co

Mo

Ti

Al

Cr

Si

Mn

Fe

Maraging steel (parent material )

0.01

18.9

8.3

4.6

0.41

0.15

-

-

-

Bal.

Maraging steel filler

0.006

18.2

11.9

2.5

0.16

0.46

-

-

-

Bal.

Medium alloy medium carbon steel (both parent material & filler)

0.33

2.8

Max. 1.0

Max. 1.0

-

-

0.85

1.8

0.35

Bal.

steel filler, which was of similar

interval of 0.5 mm, employing Knoop

dissimilar metal welds of maraging steel

composition of the parent material but

micro-hardness testing machine. All the

and medium alloy medium carbon steel

with higher cobalt and aluminum and

hardness readings were obtained at a

with maraging steel filler and medium

lower molybdenum and titanium

load of 300gf.

alloy medium carbon steel filler, in the

contents and medium alloy medium carbon steel filler with matching

2.4 Mechanical testing

as-welded and post-weld heat treated conditions are shown in the Fig.2. From

The flat tensile specimens with

the figure it is evident that in the as-

used. Measured composition of the

geometry as per ASTM E8 (25mm gauge

welded (AW) condition of maraging

parent materials and filler materials is

length) and extracted from the

steel filler welds, the microstructure

given in Table 2. The dissimilar metal

transverse section of the weldment with

consists of dendritic structure with well

welds of maraging steel and medium

weld at centre of the specimen were

developed primary arms and clearly

alloy medium carbon steels were

tested on Instron 1185 universal testing

distinguishable short secondary arms.

subjected to post-weld heat treatments

machine at a cross head of 0.5 mm/min.

With the post-weld solutionising and

to study the influence of the same on

composition of the parent material were

Sub-size Charpy specimens (5mm x

aging (PWSTA) treatment, the dendritic

microstructure and mechanical prope-

10mm, notch depth-2mm) as per ASTM

features disappeared and the marten-

rties such as hardness, tensile strength

E23-28 specifications, sectioned from

site microstructure experienced coar-

and impact toughness.

the weldment with specimen axis

sening. Post-weld quenching and

2.2 Metallography

transverse to the weld joint and 'V' notch

tempering (PWQT) treatment did not

The weldment macro-microstructures of dissimilar metal welds were studied by

at the weld centre were tested on Tinius

eliminate the light etching segregation

Oslon impact testing machine at room

features.

temperature.

The as-welded (AW) microstructure of

Leitz optical microscope. Modified Fry's

Both the above tests were also carried

medium alloy medium carbon steel filler

reagent (50ml HCl, 25ml HNO3, 1g CuCl2

out on the parent materials with the

weld consist fully dendritic structure in

same standard specifications. Scanning

addition to acicular product in the

electron microscopy was done to make

transgranular location (Fig.2). Post-

the fractographic analysis of both tensile

weld solutionising and aging (PWSTA)

and impact specimens. A minimum of

treat-ment at 815 O C resulted in

metallography of various regions using

and 150ml water) was used to etch maraging steel weld and 2% nital (2ml HNO3 and 98ml methanol) was used to etch medium alloy medium carbon steel weld. The respective etchants were also used to etch fusion zone, heat affected

three tensile and impact tests were

development of acicular product and

carried out in each condition.

fine precipitates while transgranular product and light etching phase persist.

zone and parent material regions.

When subjected to post-weld quenching

2.3 Hardness measurement

3.0 RESULTS AND DISCUSSION

Micro-hardness survey was carried out

3.1 Microstructure

across the cross section of the weld

The weld zone microstructures of

beads of all the weldments, with an

47

and tempering (PWQT) treatment the dendritic features disappeared and martensitic microstructure experienced coarsening.

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

(a) Maraging steel filler

(b) Medium alloy medium carbon steel filler

Fig.2 : Optical microstructure of weld centre of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with (a) maraging steel filler (b) medium alloy medium carbon steel filler, in various post-weld heat treated conditions

3.2

Hardness

decreasing trend near the fusion

3.2.1 Dissimilar metal welds of maraging steel to medium alloy medium

carbon

steel

with

maraging steel filler The hardness survey across the transverse section of the dissimilar metal weld of maraging steel and medium alloy medium carbon steel in the AW condition is shown in the Fig.3a. The hardness in the fusion zone is mostly same as that of the maraging steel

parent

material

except

a

steel parent material and weld to rise to

boundary of medium alloy medium

550 HK from 350 HK in the as-welded

carbon steel. The reason for this being

condition. There is marginal decrease in

the presence of austenite formed due to

the hardness of medium alloy medium

diffusion of manganese [25].

carbon steel (Compare Fig. 3a and

Fig.3b shows the hardness survey across the PWSTA dissimilar weldment of maraging steel and medium alloy medium carbon steel. It is known that the maraging steel gains its strength due to precipitation of intermetallic compounds during aging treatment. This made the hardness of the maraging

48

Fig. 3b) due to solutionising and aging temperatures being more than the quenching and tempering temperatures. There is a dip in the hardness value in the weld very close to the fusion boundary of medium alloy medium carbon steel as the austenite present due to the diffusion of manganese did not respond to the solutionising and

P. Venkata Ramana - Dissimilar Metal Gas Tungsten Arc Weldments of........................ Effect of Post-weld Heat Treatments

Fig.3 : Hardness traverse across the dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with maraging steel filler in various post-weld heat treated conditions (a) As-welded (b) Solutionised and Aged (c) Quenched and tempered

aging heat treatment.

alloy medium carbon steel filler

The hardness survey across the PWQT

Fig. 4a shows the dissimilar weld of

dissimilar weldment of maraging steel

maraging steel and medium alloy

and medium alloy medium carbon steel

medium carbon steel in the AW

is shown in the Fig. 3c. It is clear from

condition. The hardness of the fusion

the figure that the maraging steel parent

zone is high compared to that of the

material and maraging steel weld did

heat affected zone of maraging steel

not respond to the quenching and

whereas it is low compared to that of the

tempering, whereas the hardness of

heat affected zone of medium alloy

medium alloy medium carbon steel

medium carbon steel. It is noticed that

steel weld with low carbon martensite from the maraging steel, diffusion of manganese from medium alloy medium carbon steel weld to the heat affected zone of maraging steel and also may be due to the coarse grain structure formed near the fusion boundary of maraging steel as it is exposed to high temperature during the welding process.

increased as compared to that in as-

the hardness showed considerable

Fig. 4b shows the hardness of the

welded condition(Fig. 3a) as it

decrease, partially along the fusion

dissimilar weld of maraging steel and

responded to the quenching and

boundary of maraging steel and

medium alloy medium carbon steel, in

tempering treatment.

adjacent region, in the heat affected

the PWSTA condition. From the figure it

zone of maraging steel. This decrease in

is observed that the hardness of

3.2.2 Dissimilar metal welds of maraging steel to medium alloy medium carbon steel with medium

the hardness can be attributed to the

maraging steel is higher than that of the

dilution medium alloy medium carbon

weld and medium alloy medium carbon

49

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

steel. The increase in the hardness of

filler weld and medium alloy medium

steels responded to their respective

the maraging steel is due precipitation

carbon steel parent material have

heat treatments with high hardness

hardening of maraging steel. The

responded to the quenching and

(Maraging steel - nearly 550 HK and

medium alloy medium carbon steel weld

tempering, with increase in the

Medium alloy medium carbon steel -

and parent material show low hardness

hardness as compared to the as-welded

nearly 650 HK). Maraging steel showed

due to the over tempering due to

condition (Fig. 4a). The maraging steel

slight decrease in the hardness due to

solutionising and aging temperatures.

did not respond to the quenching and

the quenching but did not respond to

In the fusion zone very close to the

tempering temperatures. In the fusion

the tempering temperature. Medium

fusion boundary of maraging steel is

zone it is observed that the hardness

alloy medium carbon steel showed

observed to the presence of austenite

decreased close to the fusion boundary

lower hardness, when subjected to

formed due to the diffusion pheno-

of maraging steel. This is due to the

solutionising and aging due to over

menon as mentioned earlier.

dilution of low carbon martensite and

tempering. In all the heat treatment

presence of austenite.

conditions, always there is a consider-

The hardness survey across the

In summary, it is observed that the in the

able decrease in the hardness along the

medium alloy medium carbon steel, in

as-welded condition the medium alloy

interface of maraging steel medium

the PWQT condition is shown in the

medium carbon steel displayed high

alloy medium carbon steel due to

Fig. 4c. It is clear from the figure that

hardness compared to that of maraging

dilution and diffusion effects.

the medium alloy medium carbon steel

steel in the same condition. Both the

dissimilar weld of maraging steel and

Fig.4 : Hardness traverse across the dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in various heat treated conditions (a) As-welded (b) Solutionised and Aged (c) Quenched and tempered

50

P. Venkata Ramana - Dissimilar Metal Gas Tungsten Arc Weldments of........................ Effect of Post-weld Heat Treatments

3.3 Tensile properties The tensile properties of dissimilar metal welds with maraging steel filler and medium alloy medium carbon steel fillers, in different heat treatment conditions, are shown in Table 3. Parent material properties are given Table 4 for ready reference. 3.3.1 Dissimilar metal welds of maraging steel to medium alloy medium

carbon

steel

with

maraging steel filler From the Table 3, it is evident that the dissimilar metal welds of maraging steel and medium alloy medium carbon steel in PWSTA condition has high strength

and very low ductility compared to that of the weld joints in AW and PWQT conditions. Fig.5 shows the fracture location of the tensile samples. In the AW condition the fracture occurred in heat affected zone of maraging steel close to the fusion boundary. This due to the low hardness of the maraging steel (Fig. 3a). In the weld joint in PWSTA condition the fracture occurred in the weld close to the fusion boundary of medium alloy medium carbon steel. This is may be attributed to the presence of low hardness region in fusion zone (Fig. 3b).

In the PWQT weld joint the fracture occurred in the maraging steel. This may be attributed to the following: due to quenching and tempering the medium alloy medium carbon steel gains strength whereas the maraging steel remains unaffected with low strength. Moreover the as the maraging steel is exposed to higher temperatures during the welding process the heat affected zone close to the fusion boundary inherits the low hardness coarse grain structure. The fractographs of the tensile samples of dissimilar metal welds in AW, PWSTA and PWQT shown in Fig.6 reveal that the dimpled structure is in tune with

Table 3 : Tensile properties of dissimilar metal welds of maraging steel to medium alloy medium carbon steel

Medium alloy medium carbon steel filler

Maraging Steel Filler Material

YS (MPa)

UTS (MPa)

El.(%)

Loction of Failure

YS (MPa)

UTS (MPa)

El.(%)

Loction of Failure

As-welded

970

1045

11.4

Maraging steel

942

1007

11.8

Close to FB of Maraging Steel

Wolutionised and Aged

1307

1337

0.4

Weld (close to FB of MAMCS)

0

719

0.02

Weld

Table 4 : Parent material properties in various heat treated conditions

Material

Maraging steel

Medium alloy medium carbon steel

Condition

YS (MPa)

UTS (MPa)

El. (%)

Impact Toughness (J)

Solutionised

950

1000

12

110

Solutionised and aged

1600

1750

7.5

40

Quenched and tempered

844

1015

18.6

156

Annealed

779

977

22.3

31

Solutionised and aged

1564

1790

11

26

Quenched and tempered

1458

1815

12

24

51

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

ductility of weld joints in AW and PWQT conditions, whereas the brittle features of facets with cleavages are in tune with the very low ductility of the weld joint in PWSTA condition.

Maraging Steel

Medium Alloy Medium Carbon Steel

3.3.2 Dissimilar metal welds of maraging steel to medium alloy medium carbon steel with medium alloy medium carbon steel filler Table 3 shows that the strength of dissimilar metal weld joint in PWQT condition is marginally higher than that of the joint in AW condition, whereas the ductility of the AW condition joint is marginally higher than that of the joint in PWQT condition. It is observed that the weld joint in PWSTA condition failed without any yielding.

Fig.5 : Fracture location of tensile samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with maraging steel filler in various heat treated conditions

Fig.7 shows the fracture location of the dissimilar metal weld joints. In the AW condition dissimilar metal weld joint, the fracture occurred close to the fusion boundary of maraging steel. This may be due the low hardness region at the fusion boundary of maraging steel (Fig. 4a). In the PWSTA dissimilar metal weld joint the fracture occurred in the fusion zone though there is a low hardness region along the fusion boundary of maraging steel (Fig. 4b). This may be attributed to the temper embrittlement of the medium alloy medium carbon steel weld. The fracture in the dissimilar metal weld in PWQT condition occurred in the maraging steel. The weld and medium alloy medium carbon steel respond to the quenching and tempering treatment and gain strength and hardness where as the maraging steel remain in the solutionised condition with low hard-ness. This makes the joint to fail in the maraging steel (Fig. 4c). Fig.8 shows the fractographs of the tensile samples of dissimilar metal weld joints. The fine dimpled structure of the fracture surfaces in the weld joints in AW and PWQT conditions are in tune with high ductility values compared to that of the PWSTA condition weld joint. The brittle morphology with cleavages sub-stantiates the failure of the weld joint, in PWSTA condition, before yielding. To summarize, in dissimilar metal welds, if the strength is the criterion dissimilar metal weld of maraging steel and medium alloy medium carbon steel with maraging steel filler in PWSTA condition may be used. If the ductility is the criterion dissimilar metal weld of maraging steel and medium alloy medium carbon steel either with maraging steel filler or medium alloy medium carbon steel filler may be used. If both strength and ductility are the criterion dissimilar metal weld of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in PWQT condition may be preferred.

Fig.6 : Fractographs of tensile samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with maraging steel filler in various heat treated conditions

52

P. Venkata Ramana - Dissimilar Metal Gas Tungsten Arc Weldments of........................ Effect of Post-weld Heat Treatments

3.4 Impact toughness

Maraging Steel

Medium Alloy Medium Carbon Steel

Table 5 presents the Impact toughness of the dissimilar metal weld joints, with maraging steel filler as well as medium alloy medium carbon steel filler, in as-welded (AW), post-weld solution treated and aged (PWSTA) and Post-weld quenched and tempered (PWQT) conditions. Parent material impact toughness properties are presented in Table 4. 3.4.1 Dissimilar metal welds of maraging steel and medium alloy medium carbon steel with maraging steel filler

Fig.7 : Fracture location of tensile samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in various heat treated conditions

From Table 5 it is clear that the order of toughness in dissimilar metal welds is that the impact toughness of weld joint in PWQT condition is high compared to that of the weld joint in AW condition which in turn is higher than that of the weld joint in the PWSTA condition. From Fig.9 which shows the impact samples, it is observed that the crack path is in tune with the toughness values with longer curved path for ductile welds and shorter straight path for brittle weld. Fig.10 shows the fracture features of the weldments. Fine dimpled fracture surface is evident for the welds in AW and PWQT conditions. This may be due presence of more low carbon martensite in the maraging steel weld as one of the adjacent parent materials is maraging steel. The weld in PWSTA exhibited fracture surface with cracks. This may be due to the precipitation hardening of low carbon martensite in maraging steel weld and over tempering of the high carbon martensite in the maraging steel weld diluted from medium alloy medium carbon steel. 3.4.2 Dissimilar metal welds of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler From Table 7 it is evident that the toughness value of the welds in AW and PWQT conditions is almost same. The weld in PWSTA condition exhibit very low toughness compared all other welds mentioned in the Table. Both the welds in AW and PWQT conditions contain a mixture of hard high carbon martensite of medium alloy medium carbon steel and soft low carbon martensite. The marginal difference in the toughness value of the weld in AW condition can be attributed to the presence of untempered high carbon

Fig.8 : Fractographs of tensile samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in various heat treated conditions

martensite. This untempered martensite when tempered during PQWT process results in marginal increase in the toughness value. The very low toughness in the PWSTA

53

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

Table 5 : Impact toughness of gas tungsten arc weldments in various post-weld heat treated conditions

Impact Toughness (J) Weldment

Maraging steel filler Medium alloy medium carbon steel filler

Post-weld condition

Maraging steel filler

Medium alloy medium carbon steel filler

As-welded

32

34

Solutionised and aged

4

2

Quenched and tempered

40

35

condition can be attributed to the

1. Maraging steel responded to

temper embrittlement of the medium

solutionising and aging whereas

alloy medium carbon steel weld.

medium alloy medium carbon steel

The crack paths are similar for the welds in AW and PWQT conditions as shown in

responded to quenching and tempering treatment.

Fig.11. The weld in PWSTA exhibit

2. In the as-welded condition, medium

straight crack path showing low

alloy medium carbon steel displayed

toughness. From Fig.12 it is clear that

high hardness compared to that of

the welds in AW and PWQT exhibit high

maraging steel in the same

toughness with fine dimpled fracture

condition.

surface. The fracture surface of weld in PWSTA exhibit fibrous structure with macro cleavages. The fibrous structure can be attributed to the presence of low carbon martensite diluted from the maraging steel to medium alloy medium carbon steel weld. In summary, it is observed that the

5. If the strength is the criterion dissimilar metal weld of maraging steel and medium alloy medium carbon steel with maraging steel filler in PWSTA condition may be used. 6. If the ductility is the criterion dissimilar metal weld of maraging steel and medium alloy medium

3. Maraging steel showed slight

carbon steel either with maraging

decrease in the hardness due to the

steel filler or medium alloy medium

quenching but did not respond to

carbon steel filler may be used.

the tempering temperature.

7. If both strength and ductility are the

4. Medium alloy medium carbon steel

criterion dissimilar metal weld of

showed lower hardness, when

maraging steel and medium alloy

subjected to solutionising and aging

medium carbon steel with medium

dissimilar metal weld of maraging steel and medium alloy medium carbon steel

due to over tempering.

Maraging Steel

Medium Alloy Medium Carbon Steel

with maraging steel exhibited high toughness compared to the other weldments whereas the dissimilar metal weld with medium alloy medium carbon steel filler exhibited the lowest impact toughness.

4.

CONCLUSIONS

Influence of post-weld heat treatments on the microstructure and mechanical properties of dissimilar metal welds of maraging steel and medium alloy medium carbon steels has been investigated. Following observations are made:

Fig.9: Impact test samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with maraging steel filler in various heat treated conditions

54

P. Venkata Ramana - Dissimilar Metal Gas Tungsten Arc Weldments of........................ Effect of Post-weld Heat Treatments

Fig.10: Fractographs of impact samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with maraging steel filler in various heat treated conditions Maraging Steel

Fig.12 : Fractographs of impact samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in various heat treated conditions

Medium Alloy Medium Carbon Steel

alloy medium carbon steel filler in PWQT condition may be preferred. 8. Dissimilar metal weld with maraging steel filler, in quenched and tempered condition, exhibited

high toughness

compared to the other weldments whereas the weld with medium alloy medium carbon steel filler, solutionised and aged condition exhibited low toughness.

ACKNOWLEDGEMENTS Financial assistance from Defence Research Development Organization Fig.11 : Impact test samples of dissimilar metal gas tungsten arc weldment of maraging steel and medium alloy medium carbon steel with medium alloy medium carbon steel filler in various heat treated conditions

(DRDO)

is

gratefully

acknowledged.

The authors would like to thank Dr. G. Malakondaiah, Director, Defence Metallurgical Research Laboratory, Hyderabad for his continued encourage-ment and permission to publish this

55

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

work. The authors also thank Structural

6.

Failure Analysis Group and Metal

Decker R.F. and Floreen S.,

and Rodriguez P. Weld. J. (1997),

Maraging steels: Recent Develop-

76, p.135s.

Working Group for help in metallography

ments and Applications, in: Wilson

and heat treatment. One of the authors

R. K. (Ed.), TMS-AIME, Warrendale,

(P. Venkata Ramana) thanks the

PA, (1988), p.1.

manage-ment of Mahatma Gandhi Institute of Technology, Hyderabad for

7.

Vasudevan V. K., Kim S. J. and Wayman C. M., (1990), Metall.

permission and encouragement to carry

Trans. A, 21, p.2655.

out this work. 8.

Sha W., Cerezo A. and Smith G.D.W., (1993), Metall. Trans. A, 24, p.1221.

REFERENCES 1.

Philip T. V. and McCaffrey T. J. (ed), (1993), ASM Handbook, vol.1, p.1118.

2.

Olson G. B., "Overview: Science of Steel," Innovations in Ultrahighstrength steel Technology, (ed) by G. B. Olson, M. Azrin, and E. S.

4.

(1993), Metall. Trans. A, 24, p.1233. 10. Sha W., Cerezo A. and Smith G.D.W., (1993), Metall. Trans. A, 24, p.1241. 11. Sha W., Cerezo A. and Smith G.D.W., (1993), Metall. Trans. A, 24, p.1251.

34th Sagamore Army Materials

(2003), Acta. Mater. 51, p.101. 13. Lang F. H. and Kenyon N., Bulletin

Tomita Y., (1991), Mat. Sci. and

159, Welding Research Council,

Technol. 7, p.81.

Engineering Foundation, New York,

Malakondaiah G., Srinivas M. and Rama Rao P., (1995), Bull.Mater.Sci.

Floreen S. and Decker R. F., Source Book on Maraging steels, Decker R. F. (ed), ASM, Metals Park, OH, (1979), p.20.

M. J., (1999), Weld. J. 78, p.329s 18. Nelson T. W., Lippold J. C. and Mills M.J., (2000), Weld. J. 79, p.267s 19. Naffakh, H., Shamanian, M. and Ashrafizadeh F., (2008), J. of Mater. Sci., 43, p. 5300. 20. Bala Srinivasan P. and Satish Kumar M. P., (2009),

Mater. Chem. and

Phys. 115, p.179. 21. Sireesha M., Shaju K. A., Shankar V. and Sundaresan S.,(2000), J. of Nucl. Mater279, p.65. 22. DuPont J. N. and Kusko C. S., (2000), Weld. J. . (2000), 86, p.

Wright, (1987), Proceedings of the

18, p.325. 5.

Sha W., Cerezo A. and Smith G.D.W.,

12. Guo Z., Sha W. and Vaumousse D.,

Research Conference, p.3. 3.

9.

17. Nelson T. W., Lippold J. C. and Mills

(1971).

51s. 23. Yang, Y. K. and Kou, S, (2008), Sci. and Technol. of Weld. and Join. 13, p. 318. 24. Das C. R., Bhaduri A. K., Srinivasan G., Shankar V. and Mathew S.,

14. Garrison W. M. Jr., J. of Met. (1990), 42(5), p.20.

(2009), J. of Mater. Process. Technol., 209, p.1428.

15. Barnhouse E. J. and Lippold J.C., Weld. J. (1988), 77, p.477s. 16. Albert, S. K., Gills, T. P. S., Tyagi, A. K., Mannan, S. L., Kulkarni, S. D.,

56

25. Venkata Ramana P., Madhusudhan Reddy G., Mohandas T., A.V.S.S.K.S. Gupta, (2010), 31, p.749.

Mat. and design.

CEOBSP AWARD

Root Cause Analysis of Failure in Hot and Cold Mixing Point in Hydrogen Generation Unit (HGU)due to Thermal Fatigue Phenonmenon Mahendra Pal*, Mayank Banjare Indian Oil Corporation Limited, Guwahati Refinery, PO-Noonmati, Assam, Guwahati -781 020

ABSTRACT In a Process unit there are several streams that are exchanging heat to optimize the unit operation. In the HGU at IOCL, Guwahati refinery repetitive failures were observed in a 2” Ô, SS 304 pipe at this hot and cold mixing point. The investigation revealed that the two streams were handling fluid at a temperature of 40oC and 160oC, the difference being ? 120oC. These huge temperature differences lead to thermal gradient across the wall thickness of the pipe and also along the length of the pipe surface in the flow direction. The inner surface of the pipe seeing a higher temperature than the outer surface and therefore more expansion at inner surface. Due to this thermal fatigue phenomenon and hindered expansion severe stresses were observed at the inner surface of pipe leading to crack initiation and further propagation across the wall thickness. As a temporary measure the joint was replaced with identical pipe with higher thickness (schedule), and as a permanent solution it was suggested to replace the mixing point with an injection “Quill” design to avert the huge thermal gradient Key words: Thermal gradient, thermal fatigue, Quill , process mixing point

1.0 INTRODUCTION The reliability of a process unit operation

dependent units like Hydro treater unit

2.0

and MS-quality up gradation units.

DESCRIPTION OF HGU

BRIEF PROCESS

is to a large extent dependent on the

In a process plant where several

The HGU at Guwahati Refinery (GR) is a

reliability of its mechanical equipments.

streams are exchanging heat & mass, a

10000 TPA (1250 KG/HR) plant which

In this case, the reliability of the process

sound engineering design will help to

produces hydrogen of 99.9% purity.

equipments like column, vessels, heat

minimize, if not completely eliminate,

This hydrogen is primarily used in hydro-

exchangers, piping, pumps, compre-

the failures due to large variations in the

treater unit and MSQ unit for producing

ssors are of paramount importance for

temperature profiles of these process

diesel, ATF, MS and kerosene. The

safe and reliable operation and the

streams. This paper describes about the

process licensor is M/s KTI-BV,

profitability of the unit operation. The

repetitive failures experienced in the 2"

Netherlands. The feed is light Naphtha

outage of hydrogen generation unit due

Ô, SS 304 pipe at hot and cold mixing

and off gas.

to failures by leakage in the process

point. Temporary measures under taken

pipeline will not only lead to upset in the

and permanent solution suggested to

unit operation but also cause indirect

combat this chronic failure are also

throughput loss / shutdown of its

discussed in the paper.

* Corresponding author. E-mail : [email protected]

63

The Hydrogen Unit is divided into the following sections: 1)

Feed preheat.

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

2) 3)

Hydrogenation. De-sulphurisation

CH4 + H2O and

chlorination. 4)

Pre reforming.

5)

Reforming.

condensate separator) and exchangers

CO + 3H2

de-

(Endothermic) CO + H2O

(PSA) section for purifying the final

CO2 + H2 (Exothermic)

Pre-reformer effluent goes to reformer

6)

Heat recovery.

section where it is mixed with additional

7)

High temperature shift conversion.

quantity of steam and then superheated

8) 9)

and further to pressure swing adsorber

o

hydrogen gas to 99.9 % purity. 2.1 Location of the failed mixing point: The dia. 2", SS-304 hot and cold mixing point, is located in the down stream of

Low temperature shift conversion.

up to 630 C . This preheated feed then

Boiler feed water conditioning and

enters reformer furnace at top section

vessels V-07 (hot condensate vessel)

steam generation system.

through inlet pigtails connected to 36

and V-08 (cold condensate vessel). The

nos. of tubes. The reformer is operated

temperatures of the streams are 160oC

at steam to carbon ratio of 2.8 in design

and 40oC respectively. The isometric

feed case.

sketch below (Fig. 1) shows the layout

10) Pressure swing adsorption system (PSA). The feed light naphtha from CDU (crude distillation unit) and off gas from LRU (LPG recovery unit) is preheated to 250oC in the preheat section and sent to hydrogenation section. LRU off gases contain significant amount of olefins and light naphtha contains mercaptans as well as traces amount of heavy metals such as arsenic, lead, vanadium, copper, which are catalyst poison. In the hydrogenator, olefins are saturated. The mecaptans are converted to hydrogen

The conversion of methane with steam to CO and H2 is strongly favored by high

of the piping configuration and the location of the failed mixing point.

temperature, low pressure and high

2.2 Material of construction (MOC)

steam ratios in the presence of nickel

and operating parameters:

based catalyst. Conversion reaction

Line size : dia. 2”

takes place in tubes in presence of the catalyst. The normal reformer outlet temperature is 850 oC. CH4 + H2O CO + 3H2 CO

+ H2O CO2 +

H2

MOC of pipe : ASTM A-312 Gr, TP 304, schedule 40S (originally) Operating temperature : 40°C (cold stream) , 160 °C (hot stream) Operating pressure : 21.8 kg/cm2 & 21.2

sulfide. The impurities are absorbed on

The process gas is then sent to High

kg/cm2 in the hot & cold condensate

the hydrogenator catalyst. For hydro-

temperature (HT) and low temperature

lines respectively.

genation Co-Mo catalyst is used. The feed is then sent to desulfurization and de-chlorination section for chlorides and sulfur removal in the sulfur

(LT) shift conversion section. In the LT

Service : Hot & cold condensates (From

section the process gas passes through

V-07 & V-08 vessels respectively).

a series of reactors, vessel V-07 (hot condensate separator) and V-08(cold

Fluid velocities of the hot, cold & mixed

absorbers containing bed of zinc oxide with top layer as chlorine guard. The feed is then sent to pre-reformer section

V-07

where the de-sulfurised feed is mixed

Hot Stream (160oC)

with controlled quantity of steam so as to have feed to steam ratio of 2.5 kg/kg.

dia 2" dia 2"

o

It is then heated to 450 C and routed to pre-reformer. Hydrocarbons in the presence of steam react over a nickel

Cold Stream (40oC)

V-08

based catalyst to form an equilibrium mixture of methane, carbon dioxide, carbon monoxide and hydrogen. C2H6 + 2H2O =>

2CO + 4H2 (Endothermic)

Fig. 1 : Isometric Sketch of Hot and Cold Mixing Point, showing the failed location

64

Mahendra Pal - Root Cause Analysis of Failure in Hot and Cold Mix Point ................ (HGU) due to Thermal Fatigue Phenomenon

condensate streams are 0.33 m/s, 0.42 m/s & 0.75 m/s respectively with flow of 2.44m3/hr, 3.09m3/hr and 5.53m3/hr respectively. 2.3

Inspection history and repair jobs undertaken

The hydrogen generation unit (HGU) at IOCL, Guwahati Refinery was commi-ssioned in the year 2002. In May 2006, leakage was noticed for the first time since commissioning of the unit at a mixing 'Tee' due to cracking of dia. 2” cold header pipe located opposite to hot condensate entry point (at 90o). Preliminary inspection of the leaked 'Tee' was carried out by scanning with an ultrasonic thickness gauging meter of “panametrics make” to identify loss in metal wall thickness of the cold header pipe due to corrosion/erosion. There was no Fig. 2 : Photograph of Replaced mixing point modified to 'Y' joint, DP tested after replacement in 2006

wall thickness loss in the Tee at any location. The external surface of the cracked 'Tee' was also inspected by dyepenetrant testing (DP test). Surface cracks were noticed near the leaked location. Since this was the first incidence of cracking, the original angle of 90º connection (Tee joint) was changed to 45º connection ('Y' joint) in June'06 turnaround (Fig.2). A reinforcing pad was provided at the 'Y' joint for strengthening the weld joint. The original dia. 2” Ô, schedule 40S (3.91mm thickness) pipe at branch and main header was replaced with higher schedule pipe, i.e. schedule 80S (5.54 mm thick). Thus by increasing the weld area in a 45º connection along with reinforcement pad than a 90º connection, the thermal stresses were minimized. Welding of SS304 pipe and RF pad was carried out after joint preparation with E-308 electrode. After completing the replacement job of the failed 'Tee' joint with a 45o 'Y' joint, final

Fig. 3 : Photograph of Leaking portion of the mixing 'Y' joint at RF pad weld joint in 2008

DP-testing of the reinforcement (RF) pad weld joint and radiographic inspection of butt joints (4 nos) was carried out. The condition was found satisfactory. As an improve-ment in the design it was recommended to change this welded 'Y' joint at the mixing point, with a dia. 2” Ô, schedule 160 (8.74mm thick), SS304 latrolet in the next opportunity. This forged latrolet will reduce the stress concentration produced at the mixing 'Y' joint. In July 2008, the mixing 'Y' joint failed once again after staying in operation for approximately 2 years. This time the leak was noticed from the weld joint of reinforcement pad to the 2” dia pipe in the hot and cold mixing point (see Figs. 3 & 4). Thickness survey of the portion in and around the cracked location did not reveal any corrosion/ metal loss. As the recommended latrolet was not available, the cracked

Fig. 4 :Photograph of Hot & cold condensate mixing Tee point after insulation removal

mixing 'Y' joint was replaced with an available equal Tee of dia.

65

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

2”, schedule 160 (8.72 mm thick)

(American

confirming to SS 304 material. The butt

committee reports and API standards

petroleum

institute)

joints were carried out to ensure weld soundness.

welds (3 nos) were inspected using

were surveyed. Based on this an

radiography

found

"injection Quill" was recommended for

satisfactory. An RF pad was provided at

installation at the mixing point in Dec

3.0 DISCUSSION AND ANALYSIS

the 'Tee' portion for strengthening. The

2008. The design details of the quill

From the chronological sequence of

RF pad welding was DP tested, no

were worked out and the engineering

failures mentioned above, it is very clear

significant indications were observed.

design was approved through our

that the problematic zone is the mixing

and

were

The replaced failed 'Y' mixing joint was

engineering department in 2009.

Tee/'Y' point only. No leakages or

inspected using a remote visual

In Aug-2010 the unit was shut down for

failures were noticed in the straight pipe

inspection video scope (RVI) to see the

maintenance purpose. Seeing the

or elbows in either of the hot or cold

condition of the inner surface of the

criticality of this mixing point, weld joints

condensate circuit. This also confirms

pipe/'Y' weld joint. Multiple surface

and adjacent one feet region on all the

that there is no corrosion/failure

cracks were noticed in the weld joint

three sides of the Tee portion was

mechanism operating from process side

between the main header and branch

inspected by dye-penetrant test and

i.e from the condensate flowing inside

ultrasonic flaw detection (UFD). Linear

these pipes.

pipe ('Y' joint) and also on the pipe surface upstream and down stream of

indications

were

In the first instance of failure i.e May

the flow direction. (See Figs. 5 & 6).

observed on the inner surface at the

2006 the hot condensate was entering

These cracks were both linear and

'Tee' point at reinforcement pad location

the cold condensate pipe at 90o (Tee

branched cracks. The second time failure implies that the 'Y' joint design was not sufficient to accommodate the thermal stresses generated at the mixing point. This mixing point was identified as "critical injection point" for close monitoring during operation and maintenance shutdowns. For a permanent solution to this

chronic

cracking

problem,

experiences of other refineries, API

(micro

cracks)

and inner pipe surface downstream of

configuration at the mixing point).

flow direction. As the 'Quill' was not

Therefore the hot condensate at 160oC

available, this 'Tee' joint was replaced

was directly impinging the cold

with SS304 schedule 160 pipe without

condensate pipe wall opposite to the

reinforcement pad. It was realized that

flow direction. A hot spot was formed at

the reinforcement pad was also adding

this localized impingement spot where

to the stress concentration instead of

the temperatures experienced were in

acting as strengthening to the 'Y'/Tee

the order of 120 -160o C. This caused

weld joint. Welding was carried out

localized thermal stresses causing

using E 308 electrode. D.P. testing of

leakage over a period of time. It was

'Tee' joint and radiography of butt weld

thought that changing the 90o flow to an

HOT CONDENSATE FROM V-07 AT 160OC COLD CONDENSATE FROM V-08 AT 40OC Fig. 5 : Photograph of Cracks noticed using remote visual inspection (RVI) instrument on the inner pipe surface at the mixing Tee location

Fig. 6 : Sketch showing portion cracked by thermal fatigue

66

Mahendra Pal - Root Cause Analysis of Failure in Hot and Cold Mix Point ................ (HGU) due to Thermal Fatigue Phenomenon

angular flow (45o to the cold condensate

coming from V-07 vessel at 160oC meet

inspection code. As per the survey

line) would eliminate the problem as

at the mixing point where differential

conducted by NACE, “NACE Inter-

there will be uniform mixing after the

thermal expansion is experienced due to

national publication 34101” majority of

design change. Also the weld area in a

this temperature difference of 120oC.

problems experienced in injection points

45o joint being greater than 90o would

The calculated differential expansion is

were associated

distribute the stresses over this area

of the order of 2 mm in 1metre length of

injection points followed by

thereby reducing the overall stress. An

the pipe. As the unit is in continuous

mixing points and the least with process

with wash water process

additional RF pad was provided to

operation, this Tee/Y mixing joint is

chemical

further strengthen the 45o 'Y' joint.

subjected to continuous thermal cycling.

commonly faced problems at injection

However, in July 2008, leakage occurred o

once again in this modified 45 design, this time from the RF pad weld joint. This indicates that the above design was not adequate to handle the thermal stresses generated at the mixing point. It was also understood that the RF pad was actually increasing the thermal

injection

points.

The

Thermal stresses are generated at this

points are localized corrosion, erosion,

mixing joint due to the hindered

SCC, thermal fatigue, mechanical

expansion of the pipe causing crack

rupture due to pressure surge/

generation. These cracks were noticed

vibration.

primarily at the weld joint between the cold and hot line and in the inner surface of the pipeline downstream of the flow direction, as shown in Fig. 6.

The remedial measures taken to combat the failure of injection points were:(a) upgrading the material of construction, (b) increasing inspection frequency, (c)

stress by acting as stress raiser point.

The 'Tee' weld joint and RF pad is a

upgrading the injection type i.e

The extensive surface cracks observed

stress raiser and the cracks were

providing an “quill” , (d) process change,

in the failed sample inner surface by RVI

initiated easily at the toe of the weld

(e) piping configuration change. Of the

instrument indicates that the expansion

causing leakage from this point. This

above measures the most popular ones

of the inner surface seeing high

crack had further propagated to the

are (a) and (c). Both these methods

temperatures of the order of 120-160 o C

main pipe also due to the thermal

have given successful results .Therefore

is being restricted in the longitudinal and

cycling. Therefore the combined effect

it was decided to go for a injection quill

thickness direction by the adjacent

of thermal cycling and stress caused

as it was tested at other locations will

metal

thermal fatigue of the mixing Tee joint

great success. The design of the quill

pipe

experiencing

lower

temperatures. The RF pad is further

leading to its failure. As per API RP 571,

was based on good engineering practice

restricting this free expansion and

section 4.2.9, cracking is suspected

with provision of an SS304 inner liner

increasing the thermal stresses.

when the temperature swing exceeds

and retainer rings as shown in Fig. 7.

o

Because of the small size of pipe line (dia. 2") there was no benefit in changing the design from 90o 'Tee' to 45o 'Y'

o

about 200 F (93 C). In this case also the

The inner liner prevents direct contact

temperature swings are of the order of

of the hot fluid with the surface of the

120 oC.

pipe carrying cold fluid thereby preventing thermal stresses. Inspe-

joint as there was no cushion w.r.t to fluid volume once the hot fluid entered

4.0 CONCLUSION AND

the pipe carrying cold fluid to reduce the

RECOMMENDATIONS

ction, maintenance and repair of this quill will be easy after its installation as it can be easily dismantled. This will save

temperature of the mixed stream near

Refinery injection points are classified

the opposite pipe wall surface. It is to be

primarily into 3 types namely: a) Process

noted that fluid velocities of the hot and

chemical injection. eg. injection of

cold condensate streams are 0.33 m/s,

corrosion inhibitor in column overhead

Inspections of injection points shall be

0.42 m/s respectively with flow of 2.44

(b) Wash water injection; eg. to dissolve

carried out in accordance with API-570.

m3/hr and 3.09 m3/hr respectively. Had

salt deposits and wash out or dilute

Although process-mixing points do not

the cold pipe size been large say 4" or

time during shutdown and also increase the unit run length.

corrosive components and (c) Process

fall under the ambit of API-570, still it

above then this modification would have

mixing point which in our case falls

shall be followed for inspection purpose

been successful.

under the category of process mixing

as it is very comprehensive. As per API-

The cold condensate coming from V-08

point. These are also referred to as

570, injection piping circuit covers 12”

vessel at 40o C and the hot condensate

“mixing Tee” in API 570 piping

length or 3D (3 times the nominal pipe diameter) whichever is greater, in

67

INDIAN WELDING JOURNAL Volume 45 No. 1 January 2012

upstream direction from the injection point, and upto a point downstream from the injection point ending two changes in flow direction or 25 ft (7.6 m) beyond the first change of direction, whichever is less. REFERENCES 1. NACE International Publication 34101: Refinery injection and process mixing points, NACE international 2.) API 570-Piping Inspection code : Inspection, Repair, Alteration and Rerating of In-service piping system. Second edition, Oct 1998, American petroleum institute. 3. API

571-Damage

mechanism

Fig. 7: Sketch of Proposed “QUILL” design for hot and cold mixing point

affecting fixed equipment in refining industry. First edition, Dec 2003,

Notes: -

American petroleum institute.

1. Both the liners may have perforations of 10 mm dia for reducing the thermal gradient on the pipe.

4. Corrosion Manual, M&I Dept, Indian Oil Corporation Ltd.

2. Length of the liner will be approx. 1000 mm with branch connection around 300 mm from the inlet side to maintain the same velocities. The OD at inlet will be maintained as 2” and main header dia will be increased to 3” to create annular space for minimizing thermal stresses.

LIST OF ADVERTISERS IN INDIAN WELDING JOURNAL January 2012, VOL. 45, No. 1 1.

Ador Fontech Ltd.

13.

Koike Sanso Kogyo Co. Ltd.

2.

Ador Welding Ltd.

14.

Mailam India Ltd.

3.

Automation India Welding Technology

15.

MEMCO

4.

Bohler Welding Group

16.

Nederman India Pvt. Ltd.

5.

Cotmac Industrial Tdg. Pvt. Ltd.

17.

Orbitz Tours and Travels

6.

D & H Secheron

18.

Satkul Enterprises Ltd.

7.

Devidayal Chemical Inds. Pvt. Ltd.

19.

Spatter Cure Enterprises

8.

Don Bosco Maritime Academy

20.

Special Metals

9.

ESAB India Limited

21.

Sur Iron & Steel Co.

10.

Electronics Devices

22.

V Weld Equipment

11.

FSH Welding

23.

Weldwell Speciality Pvt. Ltd.

12.

GEE Limited

24.

Weldman Synergic Pvt. Ltd.

68