Effects of Dual‐Phase Region Quenching Treatment on Microstructure and Mechanical Properties of 24CrNiMo Low‐Alloy Steel Prepared by Selective Laser Melting

Abstract

In this paper, 24CrNiMo low alloy steel was successfully prepared using selective laser melting (SLM) technology. Effects of dual phase region quenching treatment on microstructure and mechanical properties of SLM 24CrNiMo low alloy steel were analyzed. The results showed that after three kinds of dual phase region quenching treatment, different martensite ‐ ferrite dual phase microstructure of the as‐quenched alloy steel was obtained. In the range of austenitizing temperature from 760°C to 820°C, the content and size of the ferrite decreased, on the contrary, the content and size of the martensite increased. Furthermore, with the austenitizing temperature increasing, the morphology of the ferrite gradually changed from acicular ferrite + polygonal ferrite to acicular ferrite, while the lath characteristics of the martensite became more and more obvious. For EBSD results, with increasing the quenching temperature, the crystallographic morphology gradually changed from columnar grains to equiaxed grains, meanwhile, the extreme value of texture strength and the average size of grains were both decreased. When the austenitizing temperature was 820°C, the microhardness and tensile strength of the as‐quenched alloy steel were much higher than that of the as‐deposited alloy steel.This article is protected by copyright. All rights reserved.