Influence of Deep Cryogenic Treatment on Microstructural Evolution and Transformation Kinetics Simulation by Finite Element Method of Low-Carbon High-Alloy Martensitic-Bearing Steel

Nowadays, deep cryogenic treatment (DCT) is taken as a promising technique for improving the performance of steel. This article is focused on the influence of different heat treatment processes involving DCT on the microstructural evolution of a high Cr-Co-Mo high-temperature-bearing steel. Moreover, a multiphysical field coupling numerical model is built to investigate the martensitic transformation kinetics during DCT. The results show that DCT significantly improves the hardness and promotes the transformation of retained austenite to martensite at low temperatures. DCT not only refines the retained austenite as thin-film morphology but also increases the precipitation of carbides and induces the carbides more homogenous distribution. This indicates that DCT promoted the segregation of carbon atoms and reduced the carbon content of martensite. The finite element model simulation shows that the retained austenite transformation is still incomplete, and the simulation results agree well with the experimental data by X-Ray diffraction and transmission electron microscope analysis. This implies that the finite element simulation can better reflect and verify the experimental results.

Automated summary

This article focuses on the influence of different heat treatment processes involving deep cryogenic treatment (DCT) on the microstructural evolution of a high Cr-Co-Mo high-temperature-bearing steel. A multiphysical field coupling numerical model is built to investigate the martensitic transformation kinetics during DCT. The results show that DCT significantly improves the hardness and promotes the transformation of retained austenite to martensite at low temperatures.