Microstructure and microhardness of heat treated 17-4 PH stainless steel Produced by lens technique

Abstract

The current study focused on optimizing heat treatment parameters of 17-4 PH stainless steel produced on a LENS platform. The fundamental objective of the current study as to attain the microhardness of the as received machined sample which was ± 400 HV. This was achieved by firstly printing 17-4 PH stainless steel coupons using LENS system. Subsequently, the coupons were subjected to various heat treatments which includes solution treatment at 1100 for 2hrs followed by furnace, air and water cooling. Furthermore, the aging temperature was varied from 400 to 510 , while the aging time was varied from 10 minutes to 10 hours. Material characterization (microstructural evolution and microhardness) of as-built and heat treated samples was conducted. The microstructure in as-built condition was inhomogeneous and became homogeneous after homogenization heat treatment. Moreover, the optimum aging temperature and time, which produced a microhardness of 400 HV, are 400 and 30 minutes respectively.