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

ABSTRACT

In this study, samples of 420 stainless steel were obtained by hot pressing from powder at temperatures from 1,100 to 1,200°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°C. Precipitation of Cr₂₃C₆ was observed after sintering at 1,200°C. This sample was the one with the highest density (99.7% densification) and hardness (771.9 HV).

KEYWORDS:

• 420 stainless steel
• hot pressing
• microstructure
• grain size
• microhardness

Acknowledgments

This work is supported by FCT (Fundação para a Ciência e a Tecnologia) through the grant SFRH/BD/147460/2019 and the reference project UIDB/04436/2020 and UIDP/04436/2020. Additionally, this work is supported by FCT with the reference project UIDB/00285/2020.

Disclosure statement

No potential conflict of interest was reported by the author(s).