Effect of Alloy Elements Segregation on Bi Heterogeneous Nucleation and Local Corrosion Activity in 1215MS Steel with Added Bi

This study detected and analyzed the composite inclusion MnSBi in 1215MS steel with added Bi. The heterogeneous nucleation interface between MnS and Bi was comprehensively studied using first‐principles calculations, and the segregation tendency of alloy elements at the interface and the effect of element segregation on nucleation and local corrosion activity are analyzed in depth. The calculation results indicate that Cr, Mo, and V can segregate at the MnS (001)/Bi (100) interface, while Co, Cu, and Ni do not segregate at this interface. As the atomic radius increases, the segregation tendency of these elements at this interface gradually shifts from being less prone to segregation to being more prone to segregation. The segregation of Cr, Mo, and V at the interface enhances the stability of the interface and facilitates the heterogeneous nucleation of Bi on MnS. The segregation of Cr and Mo at the interface has a certain inhibitory effect on the adsorption of chloride ions at the interface, while the segregation of V at the interface promotes the adsorption of chloride ions at the interface.