Microstructure evolution of austenitic stainless steels under high-cycle-fatigue loading at deep cryogenic temperature
Jijun Xin, Hengcheng Zhang, Wenjun Sun, Wei Wang, Dong Wu, Bingkun Lyu, Fuzhi Shen, Zhichun Fang, Chuanjun Huang, Laifeng Li
Abstract
In this work, the microstructure evolution and magnetic properties of the 316LN austenitic stainless steels under high-cycle-fatigue loading at liquid helium temperature (4.2 K) were assessed by using the X-ray diffractometer (XRD), electron microscopy and magnetic measurements. The microstructure was composed of a single face-centered cubic (FCC) phase, and the high local misorientation was found near the grain boundaries. Observations through the high-resolution transmission electron microscopy reveals that the deformation was dominated by the dislocation and stacking faults. The magnetic susceptibility varies slightly after cyclic loading test at 4.2 K.