Effect of QPQ on the fretting wear behavior of TP316H steel at varying temperatures in liquid sodium

In this study, TP316H steel was subjected to quench-polish-quench (QPQ) salt bath nitriding at different times. The effects of QPQ on the fretting wear behavior of TP316H steel at varying temperatures in liquid sodium were investigated. The results show that QPQ treatment significantly improves the wear resistance of TP316H due to the high hardness nitride layer. The main fretting wear mechanism of nitrided samples in liquid sodium is diffusion-tribo-oxidation-rediffusion. QPQ 90 with a thicker nitride layer has the best wear resistance, although the nitride layer cracks in high-temperature liquid sodium. As a result, QPQ treatment may be a viable option for combating the wear of TP316H steel in liquid metals.