PSI - Issue 20

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2018) 000 – 000

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Procedia Structural Integrity 20 (2019) 161–166

1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Effect of Residual Stress on the Destruction of Field Joints of Gas Pipelines Operating in Conditions of the North Nikolay I. Golikov a, * a V.P. Larionov Institute of the Physical-Technical Problems of the North of the Siberian Branch of the RAS, 1, Oktyabrskaya St., Yakutsk, 677980, Russia Abstract Welding residual stresses are determined by algebraic summation of stresses by the effect of external loading and can have a significant impact on the performance of welded joints. The present article examines the effect of residual welding stress on the destruction of circumferential butt welds of the gas pipeline sections. The features of the distribution of the welding residual stresses of annular welded pipe joints are considered. It has been established that thin-walled tubes are formed in the inner layers of the sealing elements with growing tension pins forming inside. Analysis of destruction of ring welded joints of the underground and underwater sections of the pipeline was carried out. The welding residual stresses were investigated with X-ray diffraction technique. It is shown that the initiation and growth of macrocracks in the field joints of thin-walled main gas pipelines occur in the heat-affected zone from the interior face of the pipe wall in the zone of high tensile residual welding stress. Analysis of the destruction of real welded joints of gas pipelines has proved that the residual welding stress is the main factor that influences the development of brittle and fatigue cracks in them. 1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Effect of Residual Stress on the Destruction of Field Joints of Gas Pipelines Operating in Conditions of the North Nikolay I. Golikov a, * a V.P. Larionov Institute of the Physical-Technical Problems of the North of the Siberian Branch of the RAS, 1, Oktyabrskaya St., Yakutsk, 677980, Russia Abstract Welding residual stress s are determined by algebraic summation of stresses by the effect of external loading and can have a signifi ant impact on the performance of welded joints. The present article examines the effect of residual welding stress on the destructi n of circumferential butt welds f the gas pipeline sections. The fe tures of th distribution of the weldi g residual stress s of a nular w lded pipe joints are considered. It has been established that thin-walled tubes are formed in the i ner layers of the sealing elements with gr wing tension pins forming inside. Analysis of destruction of ring welded joints of the undergr und and underwater sections of t pipeline w s carried out. The welding residual stresses were investigated with X-r y diffraction techniqu . It is shown that the initiation and growth of macrocracks in the field joi ts of thin-wall main gas pipelines ccur in the heat-affected zon fr m the interior face of the pipe wall in the zone of high tensil residual welding stress. Analysis of the destructio of real welded joints of gas pipelines has proved that the residual welding stress is the main factor that influences the development of brittle and fatigue cracks in them.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers

Keywords: Welded joint; Residual welding stress; Heat-affected zone; Low-alloyed steel; Gas pipeline; crack Keywords: Welded joint; Residual welding stress; Heat-affected zone; Low-alloyed steel; Gas pipeline; crack

1. Introduction It is known that, revealed that residual stress is algebraically summed with the stress from the external load. Therefore, tensile residual welding stress (RWS) has a significant influence on crack growth at fatigue failure. 1. Introduction It is known that, revealed that residual stress is algebraically summed with the stress from the external load. Therefore, tensile residual welding stress (RWS) has a significant influence on crack growth at fatigue failure.

* Corresponding author. Tel.: +7-411-235-8869. E-mail address: n.i.golikov@mail.ru * Correspon ing author. Tel.: +7-411-235-8869. E-mail address: n.i.golikov@mail.ru

2452-3216 © 2019 The Author(s). Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers 2452 3216 © 2019 Th Author(s). Publis d by lsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the ILEE-2019 organizers 10.1016/j.prostr.2019.12.133