Experimental and theoretical investigations on Si content induced rolling deformation uniformity and martensitic transformation for 301 stainless steel ultra-thin strip

The industrial challenge in producing ultra-thin, wide-width precision strip of 301 stainless steel with extreme hardness lies in achieving high martensite content and uniform deformation under low cold rolling deformation due to limitations in rolling equipment. To provide deeper insight into this issue, the influences of Si content (0.58 wt.% and 1.41 wt.%) and strain (10% and 20%) on cold rolling deformation homogeneity and strain-induced martensitic transformation in 301 austenitic stainless steel were studied. The results demonstrated that increasing cold rolling deformation in 301 stainless steel exacerbates deformation heterogeneity, with strain-induced martensite preferentially forming in localized high-strain regions. Although higher strains promote more martensite formation, the resulting distribution remains inhomogeneous. Owing to the small difference in Si content between grain boundaries and grain interiors, increasing Si content lowers the austenitic stacking fault energy in both regions, thereby promoting dislocation slip and enhancing deformation uniformity. Combined experimental and theoretical approaches confirm that Si addition enables the production of ultra-thin precision strip of 301 stainless steel with refined grain uniformity and high martensite content under low cold rolling deformation.