Improving corrosion resistance in sintered 304L stainless steel using shot blasting

Sintering atmosphere conditions can affect the corrosion resistance of sintered 304L stainless steel. In addition, surface modifications can improve surface finish and corrosion resistance. In this study, 304L stainless steel was sintered under nitrogen or argon atmospheres using two different heating rates. Barrelling and zinc shot blasting were applied. Subsequently, all samples were subjected to salt spray testing for determination of their corrosion resistance. Both barrelling and shot blasting decreased the surface porosity and surface roughness. However, barrelling and shot blasting increased surface hardness. For as-sintered samples, sintering in nitrogen atmosphere slightly improved the corrosion resistance. Barrelling slightly increased the corrosion resistance of those sintered in argon atmosphere. Shot blasting significantly improved the corrosion resistance of samples sintered in argon atmosphere. However, shot blasting produced less improvement in the corrosion resistance of those sintered in nitrogen atmosphere.