Effects of surface deformation on corrosive wear of stainless steel in sulfuric acid solution

Abstract

Corrosive wear behaviors of austenitic, ferritic and duplex stainless steel in sulfuric acid solution were investigated. Transmission electron microscopy with energy dispersive X-ray, scanning electron microscopy, microhardness tester, etc. were used to study the mechanism of surface deformation of stainless steel after corrosive wear tests. The result indicated that the corrosive wear rate of austenitic stainless steel (ASS) was the highest and that of duplex stainless steel (DSS) was the lowest if the applied loads were higher than 25 N. Because martensitic transformation induced brittleness and increased corrosion rate of ASS surface, the corrosive wear rate of ASS increased largely though the surface microhardness of ASS was largely increased during corrosive wear under high loads. The corrosive wear rate of ferritic stainless steel (FSS) also increased largely under high loads though FSS had the best corrosive wear resistance under low loads. The corrosive wear rate of DSS had a linear relationship with loads. The abilities of surface deformation strengthening of two phases were very different. The investigation indicated that surface deformation strengthening of DSS with proper ratio of γ phase was one of the important methods to improve corrosive wear resistance of stainless steel.