Mechanical properties and microstructure evolution of austenitic stainless-steel sheets, deformed at sub-zero temperatures

Abstract

Stainless steels are better than carbon steels for structural applications due to their optimal blend of strength, ductility, and corrosion resistance. Austenitic stainless steels, such as AISI304, are extensively utilized in cryogenic applications owing to their remarkable formability and corrosion resistance, even at sub-zero temperatures. In this study, the deformation behaviour of austenitic stainless steel (AISI304) sheet of thickness 1.2 mm was examined through tensile testing at room temperature (25°C) and sub-zero temperatures (0ºC, −40ºC, −80ºC, −120ºC) at strain rates such as 0.01 s⁻¹,0.001 s⁻¹,0.0001 s⁻¹. Mechanical properties, microstructure, and texture evolution were analysed and interrelated across these temperature and strain rate conditions. Tensile strength exhibited an upward trend with decreasing temperature and strain rate, while yield strength decreased with decreasing strain rate and increased with lowering temperature. Microstructural changes indicated a phase transformation from parent austenite phase, with martensite fraction escalating alongside decreasing strain rate and temperature. Micro texture analysis revealed a rise in the fraction of the cube texture component corresponding to an increase in martensite fraction across materials deformed at varying temperatures and strain rates. This paper gives complete insight into the microstructure and the texture evolution during the uniaxial deformation of AISI 304 sheet at room temperature and at sub-zero temperatures.