The wear and corrosion resistance of shot peened-nitrided 316L austenitic stainless steel

摘要

316L austenitic stainless steel was gas nitrided at 570 ℃ with pre-shot peening. Shot peening and nitrid-ing are surface treatments that enhance the mechanical properties of surface layers by inducing compres-sive residual stresses and formation of hard phases, respectively. The structural phases, micro-hardness, wear behavior and corrosion resistance of specimens were investigated by X-ray diffraction, Vickers micro-hardness, wear testing, scanning electron microscopy and cyclic polarization tests. The effects of shot peening on the nitride layer formation and corrosion resistance of specimens were studied. The results showed that shot peening enhanced the nitride layer formation. The shot peened-nitrided specimens had higher wear resistance and hardness than other specimens. On the other hand, although nitriding deteriorated the corrosion resistance of the specimens, cyclic polarization tests showed that shot peening before the nitriding treatment could alleviate this adverse effect.