Effect of grain ultra-refinement on corrosion behavior of ultra-high strength high nitrogen stainless steel
By Zhang, H.; Xue, P.; Wu, L. H.; Song, Q. N.; Wang, D.; Xiao, B. L.; Ma, Z. Y.
Published in Corrosion Science
Corrosion Science
2020
Abstract
High-performance high nitrogen stainless steel (HNS) with ultra-high strength up to ?1.7 GPa and excellent corrosion resistance was successfully obtained by friction stir processing. The simultaneous enhancement in strength and corrosion resistance was mainly attributed to the grain ultra-refinement. Uniform ultrafine-grained microstructure (?225 nm) significantly improved the repassivation behavior of HNS. With significantly increased element diffusion rate and element content, the passive film formed on the ultrafine-grained HNS showed high resistance to the nucleation and growth of pits. Grain ultra-refinement was confirmed to be an effectual method for improving corrosion resistance of HNS without sacrificing strength.