Effect of surface strain strengthening on stress corrosion cracking of stainless steel

Abstract

Keyword: stress corrosion cracking; strain strengthening; surface strain; austenitic stainless steel; residual compressive stress; dislocation density; microstructure; fracture morphology; specimen surface;martensitic stainless steel; 
Abstract: This article uses surface strain strengthening (shot peening) treatment to improve the SCC tendency of austenitic stainless steel (1Crl8Ni9Ti) and martensitic stainless steel (Cr17Ni2). The main results are as follows: 1. Surface strain strengthening treatment can significantly Improve the SCC resistance of austenitic and martensite stainless steels. 2. Martensite with high dislocation density and residual compressive stress induced by plastic transformation in the surface layer are the two main factors that improve the SCC resistance of austenitic stainless steel. 3. The high dislocation density of martensite and residual compressive stress in the surface layer are the two main factors that improve the SCC resistance of martensitic stainless steel. 4. SCC of metastable austenitic stainless steel under stress corrosion conditions is essentially a cleavage-like fracture of martensite induced by plastic transformation.