usability of the submerged arc welding (saw)

205 Pages·2017·18.71 MB·English

Pavel Layus
USABILITY OF THE SUBMERGED ARC WELDING (SAW)
PROCESS FOR THICK HIGH STRENGTH STEEL PLATES
FOR ARCTIC SHIPBUILDING APPLICATIONS
Thesis for the degree of Doctor of Science (Technology) to be presented with
due permission for public examination and criticism in Silva-auditorium of
the Student Union House (103) at Lappeenranta University of Technology,
Lappeenranta, Finland on the 3rd of May, 2017, at noon.
Acta Universitatis
Lappeenrantaensis 742
Supervisor Associate Professor, Docent Paul Kah
LUT School of Energy Systems
Lappeenranta University of Technology
Finland
Professor Jukka Martikainen
LUT School of Energy Systems
Lappeenranta University of Technology
Finland
Reviewers Professor Suck-Joo Na
Department of Mechanical Engineering
Korea Advanced Institute of Science and Technology
South Korea
Adjunct Professor / Senior Scientist Odd M. Akselsen
Department of Engineering Design and Materials
Norwegian University of Science and Technology, NTNU
Norway
Opponent Professor Suck-Joo Na
Department of Mechanical Engineering
Korea Advanced Institute of Science and Technology
South Korea
ISBN 978-952-335-072-4
ISBN 978-952-335-073-1 (PDF)
ISSN-L 1456-4491
ISSN 1456-4491
Lappeenrannan teknillinen yliopisto
Yliopistopaino 2017
Abstract
Pavel Layus
Usability of the submerged arc welding (SAW) process for thick high strength steel
plates for Arctic shipbuilding applications
Lappeenranta 2017
112 pages
Acta Universitatis Lappeenrantaensis 742
Diss. Lappeenranta University of Technology
ISBN 978-952-335-072-4, ISBN 978-952-335-073-1 (PDF), ISSN-L 1456-4491, ISSN
1456-4491

Construction of reliable, economically feasible and ice-capable vessels and structures for
the Arctic has been a subject of great interest in recent years, in spite of the concerns that
the undertaking clearly faces profound technical difficulties. One of the technical
challenges for modern Arctic shipbuilding is to produce high-quality welds, due to the
fact that a weld is usually the weakest part of any structure. Welding is especially difficult
for the high strength steels (HSS), which are used in shipbuilding for weight-reduction
purposes. The submerged arc welding (SAW) process is one of the most commonly
applied welding processes in shipbuilding, because of its high productivity and the
outstanding quality of the resultant welds.
The objective of the thesis is to explore the usability, development possibilities and
parameters of high deposition rate SAW processes and their modifications for welding of
thick cold-resistant HSS plates typically used in Arctic shipbuilding applications.
Meeting this objective required in-depth understanding of the welding and material
science background, which includes the quality requirements of welded joints intended
for Arctic service as described in various standards (ISO 19906; ASME 31.3; Norsok M-
001 and Russian Maritime Register of Shipping), properties of cold-resistant HSS and
description of testing methods used to validate welding joints for low temperature
conditions.
The thesis is based on two research methods: literature review and experimental work.
The SAW process and welding requirements, cold-resistant HSS and the Arctic operating
conditions and challenges from the engineering perspective are first studied. A literature
review of materials and welding requirements for Arctic applications according to various
standards, experimental testing of advanced SAW processes and assessment of their
suitability for application to Arctic conditions, examination of the effects of the SAW
process on HSS for Arctic service, and a proposed suitable range of parameters for
welding HSS for Arctic conditions was carried out.
Based on this analysis, it became possible to design and conduct experiments to present
new experimental data that improve understanding of SAW process and its modifications
to weld thick quenched and tempered (QT) and thermo-mechanically processed (TMCP)
HSS plates. Experiments were conducted to develop high deposition rate SAW welding
procedures of modified SAW (conventional single wire, tandem wire welding, and three-
wire and four-wire arrangements) to weld several thick (12–35 mm) high strength (580–
650 MPa tensile strength) cold-resistant (intended operational temperature -40°C (cid:167) -
60°C) steel grades, i.e. E500, F500W, X70 and AB2. The welds were evaluated by a wide
range of industrial tests: analyses of chemical, microstructural and mechanical properties;
hardness tests; and cold resistance evaluation tests: the Charpy V-notch impact test, the
Nil-ductility transition temperature (NDT) test, the three-point bending (Tkb) test and the
Crack tip opening displacement (CTOD) test. Acceptable welding parameters and
recommendations were developed, and the results of the experiments show that high-
quality welds can be obtained using heat input up to 3.5 kJ/mm.
This thesis provides a practical approach and clarifies the difficulties to SAW process
parameter selection for welding thick HSS plates intended for Arctic shipbuilding
applications. The experimental results can be directly adapted to industrial applications,
and the theoretical observations can be used to gain deeper understanding of state-of-the-
art of SAW processes and its novel developments.
Keywords: Submerged arc welding, thick plates, high strength steels, Arctic conditions,
shipbuilding, advanced SAW processes, cold-resistance steels, heat input
Acknowledgements
Firstly and foremost I would like to thank Associate Professor Paul Kah, who supported
and guided me since the days I began working in the LUT Welding Laboratory in 2012.
Since that time, Paul encouraged and guided me through this journey. I learned to write
well-structured and logical academic articles among other valuable academic skills. He
always encouraged me, helped to find solutions to problems and offered his advice. I am
grateful for the great time we spend during research visits to Russia and other places. This
work has not been possible without support from Docent Paul Kah.
Secondly, I would like to express my gratitude to Professor Jukka Martikainen for the
help in my research, and giving valuable support and comments on my topic and
regarding academic world in general. It was great and enjoyable time to attend numerous
conferences and meetings with you. I also would like to express gratitude to Dr. Markku
Pirinen, project manager of ENPI CBC Project 2012-2014, who provided me with an
opportunity to work in the project. We had fun and educating experience while attending
meetings and conferences related to this project.
I would like to say warm words to my colleagues, Esa Hiltunen, Raimo Suoranta, Eric
Mvola, Dr. Xiaochen Yang, Emanuel Gyasi, Hamed Tossalotti, Dr. Jenni Toivanen and
others. I have many pleasant memories from working with you.
Additionally, I ought a deep gratitude for project colleagues from CRISM Prometey in
Saint-Petersburg, Russia, who helped me, provided some experimental materials and
valuable advice on the topic of welding and material science. I am grateful to Dr.
Vyacheslav Ryabov for organizing my research visit to Prometey during spring-summer
2014, to Dr. Victor Geza for giving valuable materials and advices on the topic of
Submerged Arc Welding. To Director General of Prometey Prof. Alexey Oryshchenko,
Prof. Alexey Ilyin, Prof. Elena Khlusova, Prof. Tamara Semicheva, Dr. Vladimir Filin,
Maxim Gusev and others colleagues.
I would like to thank reviewers of this work Prof. Odd Akselsen and Prof. Suck-Joo Na
for their willingness and for giving their valuable comments and suggestions to improve
the manuscript. Prof. Suck-Joo Na, your comments on numerical simulations allowed me
to make the work more complete and technical, and comments of Prof. Odd Akselsen on
cold resistance testing and standards helped me to improve the clarity of the results.
Additionally, I would like to thank Prof. Suck-Joo Na for acting as an opponent and
coming to attend my public examination ceremony from South Korea to Finland.
I wish to express my gratitude to Peter Jones for correcting English and fixing logic of
this work, as well as checking my other published papers. Your explanations always help
me to get a clearer big picture and find ways to improve the work. Your humour in the
comments makes the process of correction less painful and more enjoyable (cid:45).
Enormous thanks goes to my family, my parents Dmitry and Julia Lajus, who were always
encouraging me and giving priceless advices and support in academic world and other
aspects; to brothers Dmitry and Georgy who were always helping me to carry on and to
relish this journey by visiting me in Lappeenranta and sharing moments of joy; and to my
grandparents Aleksandr and Larisa Leontiev and Olga Layus, who put a lot of efforts to
help me to become a person I became.
Friends from Saint-Petersburg, Lappeenranta and elsewhere in the world who supported
me during this interesting and challenging journey – Mihai, Vasily, Arina, Pavel B., Pavel
Y., Maya, Viki, Ville, Jussi, Lauri, Heikki, Nima, Niko, Ama, Tommi, Vini, Larissa,
Timo, Petra and other friends.
Last, but not least, I would like to express deep thanks to my one and only dear
Marinochka Kovshova, who supported me thought this journey and helped me to carry
on no matter what, you know I love you so much!

Pavel Layus
April 2017
Lappeenranta, Finland
Dedicated to my grandparents

Aleksandr Leontiev Ludvig Layus
Larisa Leontieva Olga Layus

Contents
Abstract
Acknowledgements
Contents
List of publications 11
Nomenclature 13
1 Introduction 19
1.1 Motivation ............................................................................................ 19
1.2 Research Background ........................................................................... 21
1.2.1 The Arctic area and its operating conditions and challenges from
the engineering perspective....................................................... 21
1.2.2 High strength steels for shipbuilding and offshore applications . 24
1.2.3 Basic principles of the submerged arc welding process ............. 27
1.3 Objectives and focus ............................................................................ 28
1.4 Research questions ............................................................................... 29
1.5 Overview of the work ........................................................................... 29
1.6 Impact on society and the environment ................................................. 30
1.7 Limitations and scope ........................................................................... 31
2 State of the art of SAW 33
2.1 Submerged arc welding history and fields of applications ..................... 34
2.1.1 History ..................................................................................... 34
2.1.2 Applications ............................................................................. 36
2.2 Submerged arc welding process parameters .......................................... 37
2.2.1 Arc voltage ............................................................................... 38
2.2.2 Welding current ........................................................................ 39
2.2.3 Wire stickout length ................................................................. 39
2.2.4 Welding electrode diameter and type ........................................ 40
2.2.5 Flux .......................................................................................... 42
2.2.6 Welding polarity and arc blow in multiwire welding ................. 43
2.2.7 Heat input and cooling speed .................................................... 44
2.2.8 Typical joint preparations ......................................................... 46
2.3 Submerged arc welding modifications .................................................. 47
2.4 Modelling and numerical simulations of SAW ..................................... 51
2.4.1 Empirical and parametric models .............................................. 51
2.4.2 Finite element (FE) modelling .................................................. 52
2.4.3 Computational fluid dynamics (CFD) ....................................... 56
3 Properties and quality requirements of steels and welding for Arctic
conditions 57
4 Testing methods for Arctic service steels and welds 68
4.1 Charpy V-notch impact test .................................................................. 70
4.2 Crack tip opening displacement (CTOD) .............................................. 71
4.3 Nil-ductility transition temperature test (NDT) ..................................... 73
4.4 Three-point bending test (Tkb) ............................................................. 74
5 Overview of the publications 75
5.1 Publication I: Advanced SAW processes for Arctic structures and ice-
going vessels ........................................................................................ 79
5.2 Publication II: Evaluation of applicability of thick E500 TMCP and
F500W QT steel plates for Arctic service ............................................. 80
5.3 Publication III: Multi-wire SAW of 640 MPa Arctic shipbuilding steel
plates .................................................................................................... 81
5.4 Publication IV: Material and welding requirements for Arctic oil and gas
industry ................................................................................................ 81
5.5 Publication V: Bibliometric study of welding scientific publications by Big
Data analysis ........................................................................................ 82
5.6 Publication VI: Influence of alloying elements on the low-temperature
properties of steel ................................................................................. 83
5.7 Publication VII: European and Russian metals for Arctic offshore
structures .............................................................................................. 83
6 Suggestions for further study 84
7 Conclusion 84
References 91
Appendix A: Experimental data Error! Bookmark not defined.
Publications