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

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Procedia Structural Integrity 30 (2020) 40–44

© 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 There are sufficiently long periods during the operation of steel structures, for which the structures do not experience the effects of external static and / or dynamic loads, except for their own gravity. A decrease in the level of the structure stress-strain state will promote relaxation processes in the substructure of the structural material. С hanges in the substructure of 09G2S pipe steel were studied using laboratory samples. The samples were subjected to cyclic deformation in 2009 and then laid out for long-term storage. Multiple X-ray photographs of long time placed samples indicate a significant relaxation of stresses with a prolonged absence of a force field affecting the structural steel substructure. It was revealed that the experimentally determined values by the method of full width at half-maximum broadening of the diffraction lines profiles, measured in 2009 immediately after cyclic deformation of three groups of laboratory samples of low-alloy pipe steel at three different cycle stresses amplitude close to yielding, significantly decrease after holding for a long storage time in an unstressed state. It has been shown that the long-term storage of samples subjected to cyclic loading with the cycle stresses amplitude not exceeding the yield strength of structural pipe steel promotes the stress-strain state relaxation. © 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 Keywords: substructure; profile broadening; X-ray structural analysis; cyclic loading; laboratory samples; diffraction line profile; relaxation There are sufficiently long periods during the operation of steel structures, for which the structures do not experience the effects of xternal static and / r dynamic loads, except for their own gravity. A dec ease in t level of the structure stress-strain sta e will promote relaxation processes in the substructu e of the structural material. С ha ges in the substruct re of 09G2S pipe eel ere studied using laborat ry amples. The samples were subjected to cyclic deformation i 2009 and then laid out for long-term sto age. Multiple X-ray photographs of long time placed samples indicate a significant relaxation of stresses wi h a prolonged absence of a force field affecting t e structural steel substructur . It was revealed th t h e perimentally d termined values by the meth d o full w dth t half-maximum bro dening of the diffraction lin s profiles, measured in 2009 immediately after cyclic deformation o three groups of l boratory samples of low-alloy pipe ste l at thr e different cycle stresses amplitude close to yielding, signi icantly decrease after holding for a long storage time in an uns ress d stat . It has b en shown that the long-t rm storage of samples subjected to cyclic l ading with the cycle stresses amplit de not xceeding t e yi ld trength of s ructural pipe eel pr motes the tress-strain state re axation. © 2020 The Aut ors. 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 K ywords: substructur ; rofile broadening; X-ray structural analysis; cyclic loading; laboratory samples; diffraction line profile; relaxation IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Relaxation of substructure of cyclically deformed 09G2S steel Gulyaev V.P. a , Petrov P.P. b , Stepanova K.V. b, * IX Eurasian Symposium on the problems of strength and resource in low climatic temperatures (EURASTRENCOLD-2020) Relaxation of substructure of cyclically deformed 09G2S steel Gulyaev V.P. a , Petrov P.P. b , Stepanova K.V. b, * a North-Eastern Federal University named after M.K. Ammosov, Yakutsk 677007, 58 Belinskogo st., Russia b Larion v Institute of Physical-Technical Problems of the North SB RAS, Ya utsk 67 980, 1 Oktyabrskaya st., Russia a North-Eastern Federal University named after M.K. Ammosov, Yakutsk 677007, 58 Belinskogo st., Russia b Larionov Institute of Physical-Technical Problems of the North SB RAS, Yakutsk 677980, 1 Oktyabrskaya st., Russia Abstract Abstract

1. Introduction 1. Introduction

The ability of a construction to resist external loads and to function reliably is evaluated by various experimental The ability of a construction to resist external loads and to function reliably is evaluated by various experimental

* Corresponding author. Tel.: +7 411 239 06 00. E-mail address: kseniastepanova@rambler.ru * Corresponding author. Tel.: +7 411 239 06 00. E-mail address: kseniast panova@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.2020.12.008