The effects of cryogenic treatment and impact-oscillatory loading on changes in the mechanical properties and structural condition of stainless steel 12Kh18N10T

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2024-10, Vol.913, p.147007, Article 147007
• Main Authors: Chausov, Mykola, Maruschak, Pavlo, Pylypenko, Andrii, Shmanenko, Vladyslav, Brezinová, Janette, Lisnichuk, Maksym
• Format: Article
• Language: English
• ISSN: 0921-5093
• DOI: 10.1016/j.msea.2024.147007

Research findings are presented dealing with the combined effect of cryogenic treatment + impact-oscillatory loading applied in different sequences on changes in the mechanical properties of stainless steel 12Kh18N10T. One-hour long cryogenic treatment and impact-oscillatory loading (IOL) applied at room temperature were shown to be practically unable to change the mechanical properties of the steel. At the same time, IOL pre-applied at a temperature of liquid nitrogen followed by static tensioning at room temperature proved to cause significant changes in the mechanical properties of the steel. Under further static tensioning, when IOL εimp = 2.7 … 12.5 % (assigned intensity range of introducing impulse energy into steel) or, more specifically, when εimp = 9.69 %, the ultimate strength of the steel was found to reach its maximum value, increasing by 32,2 % compared to baseline, while ductility decreased by 26 %. Specific physical investigations using the TEM microscope were conducted. The analysis of the steel structure of a specimen pre-subjected to IOL in liquid nitrogen at εimp = 9.63 % indicates that under such complex loading conditions the well-known mechanism of plastic deformation by sliding changes into plastic deformation by twinning upon further static tensioning, and the strength of the steel increases.