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) 180–184

1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Investigation of the distribution of residual stresses in dissimilar thickness girth welds Mikhail M. Sidorov* Larionov Institute of Physical and Technological Problems of the North, the Siberian Branch of the Russian Academy of Science, Federal Research Center ‘Yakut Scientific Center of the Siberian Branch of the Russian Academy of Sciences’, Yakutsk, Russia, 677980 Abstract Investigation of the distribution of residual stresses in girth welds of pipes is a rather laborious process. It is not always possible to predict how residual stress fields will be formed after welding. The result depends on steel grade, technological process of welding (heat input welding, welding speeds), temperature of environment, geometrical parameters of pipes. Distribution of residual stresses in a dissimilar thickness girth butt weld of pipes with a diameter of 530 mm of low alloyed (0.9%C-2%Mn 1%Si) steel was studied. Residual stresses were measured by the X-ray method based on measurement of microdeformation of a crystal lattice of a material under its influence. The research results showed that tensile residual stresses in the girth weld were formed at the inner side of the pipe after welding. It was revealed that the magnitude and distribution of residual stresses depend on the wall thickness of the pipes. In a thinner pipe, the level of tensile residual stresses is 40-50% higher than that of a thicker pipe. Investigation of the distribution of residual stresses in welded joints can be useful for developing methods to reduce the high residual stresses that occur after welding and also at deciding of constructive and technological task in the process of welding works. 1st International Conference on Integrity and Lifetime in Extreme Environment (ILEE-2019) Investigation of the distribution of residual stresses in dissimilar thickness girth welds Mikhail M. Sidorov* Larionov Institut of Physical and Technological Problems of the North, t Siberian Branch of the Russian Academy of Science, Federal Research Center ‘Yakut Scientific Center of the Siberian Branch of the Russian Academy of Sciences’, Yakutsk, Russia, 677980 Abstract Investigation of the distribution of residual stresses in girth welds of pipes is a rather laborious process. It is not always possible to predict how residual stress fi l s will b formed after welding. The result depends on steel grade, technological process f wel ing (h at input welding, welding peeds), temperature of nvironment, g ometrical parameters of pipes. Distribution of residual stresses in a dissimilar thickness girth butt wel of pipes with a diameter of 530 mm of low alloyed (0.9%C-2%Mn 1%Si) steel was studied. Residual stresses were measur d by the X-ray method based on measurement of microdeformation of a crystal l ttic of a mat rial under its influence. The research results showed that tensile residual stresses in the girth wel were formed at the inner side of the pipe after welding. It was re ealed that the magnitud and distribution of residual stresses depend on the wall thickness of the pipes. In a thinner pipe, the level of tensile residual stresses is 40-50% higher than that of a thicker pipe. Investigation of the distribution of residual stresses in wel ed joints can be useful for developing methods to reduce the high residual stresses that occur after welding and also at deciding of constructive and technological task in the process of welding works.

© 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: residual stress; X-ray method; girth weld of pipe; trunk pipeline. Keywords: residual stress; X-ray method; girth weld of pipe; trunk pipeline.

1. Introduction Arc welding is one of technological processes of reception of welded connections of the trunk pipelines. As a 1. Introduction Arc welding is one of technological processes of reception of welded connections of the trunk pipelines. As a

* Corresponding author. Tel.: +7-4112-35-84-29 E-mail address: sidorovmm@bk.ru * Correspon ing auth . Tel.: +7-4112-35-84-29 E-mail address: sidorovmm@bk.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.2019.12.136