Investigation of mechanical and corrosion properties of plasma nitrided 17-4 PH stainless steel

Plasma nitriding (PN) is a thermo-chemical surface hardening process. Since it has many superior properties compared to other surface hardening processes, it is applied in many areas. 17-4 PH (AISI 630) stainless steel has been selected for this study. 17-4 PH stainless steel has the property of precipitation hardening. PN was applied to samples produced from 17-4 PH stainless steel at 400, 450 ° C for 12 hours under the conditions of 3 : 1 (75% N2- 25% H2) N2 / H2 gas ratio. After the PN process, the hardness of the test samples were measured and the wear tests were performed with the ball-on-disc tribometer. The nitrided samples were also subjected to salt fog tester. As a result of hardness measurements, the hardness values of PN450 and PN400 samples were found to be approximately 1130 HV0.025, 1042 HV0.025 respectively. The untreated material hardness is 361 HV1. In consequence of wear test, the PN450 coded samples showed the best wear behavior. It was observed that the samples treated with PN had corroded as a result of salt fog test.