Influence of temperature processing on the microstructure and hardness of the 420 stainless steel produced by hot pressing

In this study, samples of 420 stainless steel were obtained by hot pressing from powder at temperatures from 1,100 to 1,200 degrees C. The aim was to explore the influence of the processing temperature on their grain size, microstructure, densification and mechanical properties. The results showed that it is possible to produce dense samples at these sintering temperatures. The sintering temperature influenced the density, grain size, structural phases, and hardness of the samples. Martensite and austenite were present in the samples sintered at 1,100, 1,150, and 1,180 degrees C. Precipitation of Cr23C6 was observed after sintering at 1,200 degrees C. This sample was the one with the highest density (99.7% densification) and hardness (771.9 HV).