PSI - Issue 30

Mikhail M. Sidorov et al. / Procedia Structural Integrity 30 (2020) 149–153 Mikhail M. Sidorov, Nikolay N. Golikov and Yuriy N. Saraev / Structural Integrity Procedia 00 (2020) 000–000

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unchanged after UIT at the inner side. The experimental data correlate with the data obtained in the work of Sidorov and Golikov (2019). 4. Conclusions In the girth weld of the steel pipe (0.10%C-2%Mn-1%V-1%Nb-1%Al), compressive residual stresses were detected on the outer side and residual tensile stress were detected on the inner side of the pipe wall. Ultrasonic impact treatment of the girth weld at a speed of 0.06 m/min on the inner side of the pipe wall of strength class K60 caused transformation of residual welding stresses from tensile to compressive ones. As a result of such treatment, the maximum compressive residual stresses reached values of -100...-200 MPa. It’s shown that ultrasonic impact treatment reduces the level of tensile residual stresses and transforms them into compressive residual stresses. This can have a positive effect on the fatigue strength of the pipe girth weld. The research is executed with financial support of Russian Science Foundation, the project No. 16-19-10010. References Dmitriev, V.V., Golikov, N.I., Saraev, Ju.N., 2013. Distribution of residual stresses of butt joints obtained by stationary and pulse welding modes, VI Eurasian Symposium on the problems of strength of materials and machines for cold climate regions EURASTRENCOLD-2013. Yakutsk, Russia, 92-94. Golikov, N.I., Sidorov, M.M., 2014. Investigation of the redistribution of residual stresses in cyclic loading of welded joints, Journal of Welding International 28(12), 970-972. Kapitonova, T.A., Struchkova, G.P., Levin, A.I., Nikolaeva M.V., 2019. Analysis of statistics of accidents and failures of the Mastakh-Berge Yakutsk main gas pipeline, Journal of Petroleum Engineering 17(6), 49-57. Leggatt, R.H., 2018. Residual stresses in welded structures, International Journal of Pressure Vessels and Piping 85(3), 144-151. Larionov, V.P., Petushkov, V.G., Yakovlev, G.P., 1998. On the influence of residual stresses on the cold resistance and endurance of welded joints, In: Welding and problems of visco-brittle transition . In: Siberian Branch of the Russian Academy of Science Press. Novosibirsk, p. 459-466. Shestakov S. D., 2013. Ultrasonic surface plastic deformation for hardening and passivation by riveting: theory, technological processes and equipment, Strengthening technologies and coatings 7, 3-15. Sidorov, M.M., Golikov, N.I., Ammosov, A.P., 2010. Method of relieving residual weld stress in pipe wielded butt joints. Patent RUS 2444423. Sidorov, M.M., Golikov, N.I., 2019. Effect of ultrasonic impact treatment on redistribution of residual stresses in dissimilar thickness girth welds, IOP Conference Series: Materials Science and Engineering 681, 012039. Withers, P. J., Bhadeshia, H. K. D. H., 2001. Residual stress Part 1 – Measurement techniques, Journal of Materials Science and Technology 17, 355-365. Acknowledgments