EFFECT OF HIP ON THE MICROSTRUCTURE AND IMPACT STRENGTH OF MIM 17.4 PH STAINLESS STEEL

摘要

Previous research has proven that hot isostatic pressing (HIP) improves density and mechanical properties and decreases part dimension variation in metal injection molded (MIM) ferrous alloys. Since HIP temperatures are typically significantly lower than the MIM sintering temperature, it has been surprising to observe a marked effect on grain size and morphology from HIP processing in MIM 17.4 PH stainless steel that varies with HIP temperatures. The relationship between sintering and HIP temperatures is explored on a microscopic level by grain size and the amount and location of porosity present and on a macroscopic level by measuring impact toughness.