Roles of Inclusion, Texture and Grain Boundary in Corrosion Resistance of Low-Nickel Austenite Stainless Steel Containing Ce

Abstract

The roles of inclusion, texture and grain boundary in corrosion resistance of low-nickel austenite stainless steel containing Ce was investigated by using SEM, TEM, EBSD, XRD and testing technology of electrochemistry. The results revealed that the variation in corrosion resistance of 205 stainless steels containing Ce was higher than specimen without Ce, which depended on ∑3ⁿ boundaries and Ce modifying inclusion treatment. Ce addition to steels was prone to forming fine and dispersive Ce multi-phase inclusions containing CeAlO₃, CeS and Ce₂O₂S. When addition of Ce was up to 0.016 wt.%, its textures were characterized by pronounced γ-fiber textures comprising {111} <110> and {111} <112> components, as well as the frequency of ∑3ⁿ boundaries related to {111} <112>, {111} <110> and {112} <110> components was significantly improved, which was in favor of corrosion resistance improvement. While adding 0.023 wt.%Ce element was detrimental to corrosion resistance of stainless steel.