Work

Effect of low-temperature tempering on microstructure and mechanical behavior of ultra-high-strength medium-Mn steel

Year: 2025

Type: article

Abstract: This research comprehensively analyzed the impact of low-temperature tempering heat treatment on the microstructure and tensile properties of cold-rolled medium Mn steel. The microstructure of cold-rolled medium Mn steel consisted of blocky and film-like retained austenite (RA) and banded, blocky, and lath-like martensite. After low-temperature tempering of the cold rolled samples, the microstructure was dominated by banded and blocky martensite and some granular and blocky RA. During tempering, the austenite/martensite interface migration to the austenitic phase occured, with 18 vol.% of the blocky and film-like austenite transforming into martensite. The low-temperature tempering treatment relieved the residual stresses caused by cold rolling, the segregation of C atoms at the martensite/austenite phase interface and precipitation of nano-carbons led to an increase in yield strength of the tempered samples by 554 MPa. The surrounding harder martensitic matrix of the tempered samples contributed to the stability of RA. The high RA stability contributed to the strain hardening rate, increasing the tensile strength of the tempered sample by 282 MPa.

Source: Journal of Materials Research and Technology

DOI: 10.1016/j.jmrt.2025.08.281

Authors: Wei Liu, Zhiqiang Wu, Tao Li, Hongang Zhou, Zhihui Cai, Kui Chen

Institutions: Hunan University of Science and Technology, Taiyuan University of Science and Technology

Language: English

Topic: Microstructure and Mechanical Properties of Steels

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,640

Funders: National Natural Science Foundation of China, Natural Science Foundation of Hunan Province, Science and Technology Program of Hunan Province, Scientific Research Foundation of Hunan Provincial Education Department