The Corrosion Behaviour of Austenitic 316L Stainless Steel After Low-T Plasma Nitridation in the Physiological Solutions

Abstract

We studied the corrosion properties of low-T plasma-nitrided 316L austenitic stainless steel in the physiological solutions. The plasma nitridation was performed at different gas compositions of N2–H2 mixture at temperatures from 400 to 5008C for 1 h. The potentiodynamic anodic polarization measurements were performed in the physiological saline and Hank’s solutions at the room temperature. The corrosion resistance is dependent on the microstructure of plasma-nitrided austenitic stainless steel and the chemical composition of physiological solution. The pitting potential tends to increase without CrN precipitation, otherwise the pits are clearly seen on the plasma-nitrided samples. The S-phase formation in the microstructure improves the corrosion resistance.