Effect of low-temperature nitriding on impact-sliding wear behavior of an austenitic stainless steel at room and sub-zero temperatures

The role of the S-phase layer formed after low-temperature nitriding on the wear resistance of a 17Cr-10Ni-2Mo stainless steel at room and sub-zero temperatures was investigated by using an impact-sliding wear tester, simulating the progress of surface degradation on engineering components under dynamic loading. While the as-received samples suffered from plasticity-dominated wear, surface cracking was dominant for the nitrided samples. Both of the samples exhibited lower wear rates with decreasing test temperature. The highest contact pressure employed (3 GPa) caused spallation of the-3 mu m thick S-phase layer at room temperature, unlike sub-zero temperature. Under this highest contact pressure, the thicker S-phase layer (-6 mu m) remained intact with the substrate and provided good protection against wear at room temperature.