PSI - Issue 30

Available online at www.sciencedirect.com Available online at www.sciencedirect.com Sci nceD rect Structural Integrity Procedia 00 (2020) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2020) 000–000

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

ScienceDirect

Procedia Structural Integrity 30 (2020) 6–10

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors Abstract The article investigates the welded joints of siphon pipes of the underwater crossing of the main oil pipeline manufactured from 09G2 steel. The diameter of the welded pipes is 1220 mm, the wall thickness is 29 mm. The manufacturing of steel pipes involves thermal strengthening during accelerated cooling. The studies were performed both in the field and in the laboratory. The following studies are described: hardness measurement, its distribution along the fusion line and heat affected zone, measuring the distribution of residual welding stresses, and tensile testing of samples at room temperature. Distributions of residual welded stresses are determined from both the outer and inner walls of the oil pipeline siphon. Destructive and non destructive direct methods were used to determine the mechanical properties of the metal on standard samples of the welded joint and heat affected zone of the pipeline. Tensile strength, yield strength, and relative elongation are determined. The mechanical properties of the pipeline metal were calculated concerning the hardness. It has been established that the mechanical properties and structure of the welded joint of the pipeline metal comply with the regulatory documents, certificates, and specifications for pipelines. Analysis of the results shows that there is a tendency toward hardening of heat affected zone during multilayer welding and a decrease in ductility. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Abstract The article investigates the welded joints of siphon pipes of the underwater crossing of the main oil pipeline manufactured from 09G2 steel. The diam ter of the welded p es is 1220 mm, the wall thicknes is 29 mm. The manufacturi g of steel pip s involves thermal str ngthening during acc lerated cooling. The s udies were performed both in the field nd the laboratory. The following studies ar described: hardness measurement, its istribution al ng the fus on line and heat affected z ne, measuring the distr bution of residual welding str s es, and ten ile testing of samples at ro m temperatur . Distributions of resid al weld d tresses are determined from bo h th outer and inner walls of the oil pipeline siphon. Destructive and non d tr ctive direct m thods wer used to deter ine the mechanical prop ties of the metal on standard samples of the welde j i t and heat affected zone of th pipeline. T nsile strength, yield strength, and relative longation are determined. The mechanical properties of th pipeline m tal were calculat d co cerning the hardness. It has be n establ shed that the m chanical properties and st ucture of the welded joint of the pipeline metal comply with th regulatory document , certifica es, and spe ifications for pipelines. Analysis of the results shows that there is tendenc toward hardening of heat affected zone during multilayer welding and a d crease in ductility. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of EURASTRE COLD - 2020 guest editors K ywords: oil pipeline; underwater crossing; hardness; residual stress; pipeline, siphon. IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Investigation of the welded joints of siphon pipes of the underwater crossing of main oil pipeline IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Investigation of the welded joints of siphon pipes of the underwater crossing of main oil pipeline A.A. Antonov*, Yu.A. Yakovlev, G.G. Ammosov, Z.G. Kornilova Larionov Institute of Physical-Technical Problems of the North SB RAS, Oktyabrskaya St. 1, Yakutsk, 677980, Russia A.A. Antonov*, Yu.A. Yakovlev, G.G. Ammosov, Z.G. Kornilova Larionov Institute of Physical-Technical Problems of the North SB RAS, Oktyabrskaya St. 1, Yakutsk, 677980, Russia Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors Keywords: oil pipeline; underwater crossing; hardness; residual stress; pipeline, siphon. 1. Introduction The article discusses the underwater crossing of the main pipeline, designed to transport up to 80 million tons of 1. Introduction The article discusses the underwater crossing of the main pipeline, designed to transport up to 80 million tons of

* Corresponding author. Tel.: +7-924-465-9741. E-mail address: Santaz7@rambler.ru * Corresponding author. Tel.: +7-924-465-9741. E-mail address: Santaz7@rambler.ru

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open-access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under the responsibility of the EURASTRENCOLD - 2020 guest editors 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open-access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review u der the responsibility of the EURASTRENCOLD - 2020 gu st editors

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the EURASTRENCOLD - 2020 guest editors 10.1016/j.prostr.2020.12.002