Effect of Surface Mechanical Rolling Treatment on the Corrosion Behavior of 316L Stainless Steel

ABSTRACT A gradient nanostructure (GNS) surface layer was formed on the surface of 316L stainless steel by a double‐sided symmetrical rolling treatment (D‐SMRT) technique. To verify whether the GNS can improve the corrosion resistance of 316L stainless steel, the corrosion behavior of conventional coarse‐grain (CG) specimens and SMRTed specimens under different rolling passes in 3.5 wt.% NaCl solution was investigated by combining electrochemical testing technology and microstructural characterization. The result shows that the SMRTed specimens have better corrosion resistance due to the grain refinement and improvement of grain boundary density produced by (D‐SMRT) technique. The microstructural observations results indicate that the rolling 6‐pass has better pitting resistance, the higher density of grain boundaries contributed to improving the densification of the passivation film, making the corrosion resistance of the SMRTed specimens better than the CG.