Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (9): 205-210.DOI: 10.13251/j.issn.0254-6051.2021.09.037

• MICROSTRUCTURE AND PROPERTIES • Previous Articles     Next Articles

Effect of reversed austenite stability on strength and toughness of medium-Mn steel

Qi Xiangyu1,2, Yan Ling1,2, Li Guanglong1,2, Li Wenbin1,2, Du Linxiu3   

  1. 1. State Key Laboratory of Metal Material for Marine Equipment and Application, Anshan Liaoning 114009, China;
    2. Iron and Steel Research Institute of Angang Group, Anshan Liaoning 114009, China;
    3. State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang Liaoning 110819, China
  • Received:2021-03-27 Online:2021-09-25 Published:2021-12-09

Abstract: A quenched medium manganese steel was tempered, and the content and stability of reversed austenite at different tempering temperatures with its effect on the strength and toughness were studied. The results show that with the tempering temperature increasing from 630 ℃ to 670 ℃, the volume fraction of reversed austenite is increased from 19% to 42%, while its stability decrease constantly; and the yield strength decreases from 750 MPa to 565 MPa, the tensile strength increases from 845 MPa to 970 MPa, the impact toughness at -60 ℃ decreases from 116 J to 75 J. The large volume fraction of reversed austenite with poor stability reduces the yield strength of the steel, but improves the work-hardening ability significantly. The transformation-induced plasticity effect of reversed austenite can increase the crack initiation and propagation energy effectively under impact loading, which is the main toughening mechanism of the medium manganese steel.

Key words: reversed austenite, medium manganese steel, microstructure, TRIP effect, toughening mechanism

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