Influence of hydrogen saturation on the structure and mechanical properties of Fe-17Cr-13Ni-3Mo-0.01С austenitic steel during rolling at different temperatures

OBRABOTKAMETALLOV Vol. 23 No. 2 2021 95 MATERIAL SCIENCE In fl uence of hydrogen saturation on the structure and mechanical properties of Fe-17Cr-13Ni-3Mo-0.01 С austenitic steel during rolling at different temperatures Evgeny Melnikov a, * , Galina Maier b , Valentina Moskvina c , Elena Astafurova d Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences, 2/4 pr. Akademicheskii, Tomsk, 634055, Russian Federation a https://orcid.org/0000-0001-8238-6055, melnickow-jenya@yandex.ru , b https://orcid.org/0000-0003-3043-9754, galinazg@yandex.ru, c https://orcid.org/0000-0002-6128-484X , valya_moskvina@mail.ru , d https://orcid.org/0000-0002-1995-4205, elena.g.astafurova@ispms.ru Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science. 2021 vol. 23 no. 2 pp. 81–97 ISSN: 1994-6309 (print) / 2541-819X (online) DOI: 10.17212/1994-6309-2021-23.2-81-97 Obrabotka metallov - Metal Working and Material Science Journal homepage: http://journals.nstu.ru/obrabotka_metallov ARTICLE INFO Article history : Received: 15 February 2021 Revised: 09 March 2021 Accepted: 29 March 2021 Available online: 15 June 2021 Keywords : Austenitic steel Plastic deformation Hydrogenization Microstructure Mechanical properties Funding The work was carried out within the framework of the state assignment of the IPPM SB RAS, topic number FWRW-2019-0030. Acknowledgements The studies were carried out on the equipment of IPPM SB RAS (Center for Collective Use “Nanotech”) and NRU “BelGU” (Center for Collective Use “Diagnostics of the structure and properties of nano-materials”). ABSTRACT Introduction. The development of hydrogen energy implies a decrease in the dependence of various human activities on fossil energy sources and a signi fi cant reduction in carbon dioxide emission into the atmosphere. Therefore, the requirements for the quality of structural materials, which have the prospect of being used for storage and transportation of hydrogen, as well as for the creation of infrastructure facilities for hydrogen energy, are increasing. Therefore, the scienti fi c researches on the hydrogen-assisted microstructure and mechanical behavior of structural materials in various loading schemes are of great importance. The aim of this work is to establish the effect of chemical-deformation treatment, including rolling combined with hydrogen saturation, on the microstructure, phase composition, and mechanical properties of 316L-type austenitic stainless steel. Methods. Transmission electron microscopy and backscattered electron diffraction, X-ray diffraction, X-ray phase and magnetic phase analysis, microindentation and uniaxial static tension are utilized. Results and Discussion. It is shown experimentally that after rolling with 25 and 50 % upset, the morphology of the defect structure and the phase composition of 316L steel substantially depends on the deformation temperature (at room temperature or with the cooling of the samples in the liquid nitrogen) and on hydrogen saturation rate (for 5 hours at a current density of 200 mA/cm2). The main deformation mechanisms of the steel in rolling are slip, twinning, and microlocalization of plastic fl ow, which all provide the formation of ultra fi ne grain-subgrain structure in the samples. In addition, deformation-induced ε and α ’ martensitic phases are formed in the structure of the rolled samples. Regardless of the regime of chemical-deformation processing, grain-subgrain structures with a high density of deformation defects are formed in steel, but its morphologies are dependent on the processing regime. The experimental data indicate that both preliminary hydrogen saturation and a decrease in the deformation temperature contribute to the more active development of mechanical twinning and deformation-induced phase transformations during rolling. Despite the discovered effects on the in fl uence of hydrogen saturation on the deformation mechanisms and the morphology of a defective microstructure formed during rolling, preliminary hydrogenation has little effect on the mechanical properties of steel at a fi xed degree and temperature of deformation.These data indicate that irrespective of the morphology of the defective grain-subgrain structure, grain re fi nement, accumulation of deformation defects and an increase in internal stresses lead to an increase in the strength characteristics of the steel. For citation: Melnikov E.V., Maier G.G., Moskvina V.A., Astafurova E.G. In fl uence of hydrogen saturation on the structure and mechanical properties of Fe-17Cr-13Ni-3Mo-0.01 С austenitic steel during rolling at different temperatures. Obrabotka metallov (tekhnologiya, oborudovanie, instrumenty) = Metal Working and Material Science , 2021, vol. 23, no. 2, pp. 81–97. DOI: 10.17212/1994-6309-2021-23.2- 81-97. (In Russian). ______ * Corresponding author Melnikov Evgeny V. , Junior Researcher Institute of Strength Physics and Materials, Science of Siberian Branch of Russian Academy of Sciences, 2/4 pr. Akademicheskii, 634055, Tomsk, Russian Federation Tel: 8 (3822) 28-68-65, e-mail: melnickow-jenya@yandex.ru