Effect of sintering temperature on microstructure and properties of MIM420 stainless steel

Abstract

This paper investigates the effect of different sintering temperatures on the microstructure and mechanical properties of 420 stainless steel prepared by metal injection molding (MIM). The results show that in the temperature range of 1300 to 1360, the internal structure of MIM420 stainless steel is mainly lath martensite and the fracture mode is quasi cleavage fracture. With the increase of sintering temperature, the relative density, strength and hardness of MIM420 stainless steel increase, and the carbon and oxygen content decreases, but the strength decreases when the sintering temperature exceeds 1340. When the sintering temperature reaches 1360, the sample will be slightly over sintered, so the appropriate sintering temperature is 1340. At 1340, the relative density, hardness, bending strength and ultimate tensile strength of the sample are 98.2 ± 0.4%, 54 ± 1HRC, 1229 ± 28 MPa and 1111 ± 26 MPa respectively.