Effect of Nitrogen and Deformation Twinning on Tensile Properties of Austenitic Stainless Steels Fabricated by Metal Injection Molding

Abstract

High nitrogen stainless steel (Fe-17Cr-12Mn-3Mo-1N) fabricated by metal injection molding (MIM) method has prominent strength and ductility. However, the tensile properties are unexplainable only by the influence of nitrogen solid solution strengthening. In this study, to clarify it, we have examined tensile-deformed microstructure. Strength of high nitrogen stainless steel was three times as high as that of SUS316L, without losing ductility, and micro-deformation twinnings were observed for the steels tensile-fractured at room temperature. It is thought that high strength with high ductility of this steel is attributed to solid solution strengthening of nitrogen and the formation of deformation twinning.