The 17-4PH stainless steel was prepared by metal injection molding technology with atomized powder and thermoplastic adhesive. Through vacuum sintering and heat treatment after sintering, the samples were analyzed through hardness,metallographic analysis and salt spray. The result shows that: the microstructure of sintered MIM 17-4PH stainless steel is mainly composed of lath martensite and clumpy ferrite, and the hardness is 24HRC, and there are some corrosion spots after 12h salt spry test. After solid solution treatment at 1040 ℃, the hardness increases to 29HRC, and there is no corrosion spot after 24h salt spry test. After ageing at 480℃, the second phase particles is precipitated,dispersed in the matrix. The hardness increases to 38HRC and there are some corrosion spots after 8h salt spry test.
