Microstructure evolution and SSCC behavior of strain-strengthened 304 SS pre-strained at room temperature and cryogenic temperature
Baozhuang Sun, Yue Pan, Jike Yang, Jing Guo, Bo Zhao, Xiang Liu, Zhiyong Liu, Xiaogang Li
Abstract
In this work, microstructure and sulfide stress corrosion cracking (SSCC) of 304 stainless steel (SS) pre-strained at cryogenic and room temperature were studied. 304 SS exhibits extremely high SSCC susceptibility, which increases as pre-strain rises for the acceleration of AD and HE. Cryogenic pre-strained specimens present higher SSCC resistance. Pre-strain leads to the formation of strain-induced ε and α' martensite and increase of crystal defects such as deformation bands, twins, stacking faults and dislocation, which accelerates SSCC. Cryogenic deformation produces more martensite, and the uniform occurrence of microstructure evolution only plays a limited role in SSCC.