Effect of Silicon on the Martensitic Nucleation and Transformation of 301 Stainless Steel under Various Cold-Rolling Deformations

Abstract

A systematic study was conducted on the influence of silicon on the microstructure, stress distribution, and martensitic nucleation and transformation of 301 metastable austenitic stainless steel during cold-rolling deformation. When the deformation amount of conventional 301 stainless steel is ≤20%, the amount of martensite transformation is very small. When the deformation amount is ≥30%, the amount of martensite transformation significantly increases. The introduction of Si significantly improves the amount of martensite transformation and the uniformity of deformation. 301Si-H has a significantly higher amount of martensite in the same deformation microstructure than conventional 301Si-L with a lower silicon content. Increasing the Si content decreases the stacking fault energy of 301 stainless steel. During deformation, Si tends to cluster at the grain boundaries, reducing stacking fault width and increasing dislocation density, creating sites for shear martensite nucleation at the grain boundaries. Simultaneously, significant deformation encourages the formation of deformation twins and facilitates martensite nucleation.