Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (9): 72-78.DOI: 10.13251/j.issn.0254-6051.2021.09.012

• PROCESS RESEARCH • Previous Articles     Next Articles

Influence of heat treatment process on microstructure and properties of M2 high speed steel

Li Liangjun1,2, Zhang Jiamin1, Chi Hongxiao2, Zhou Jian2   

  1. 1. Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming Yunnan 650093, China;
    2. Special Steels Research Institute, Central Iron and Steel Research Institute, Beijing 100081, China
  • Received:2021-04-30 Online:2021-09-25 Published:2021-12-09

Abstract: Effect of heat treatment on microstructure and properties of the M2 high speed steel was studied. The results show that the microstructure of the M2 steel after quenching is quenched martensite+retained austenite+a large amount of carbides. With quenching temperature increasing, the content(mass fraction) of retained austenite in the M2 steel increases, the retained austenite after three times of tempering is basically completely eliminated, while the content of retained austenite after adding subzero treatment is higher than that after three times of tempering, which results in the improvement of strength and toughness of the steel. Comparing the microstructure and properties of the steel under different heat treatment conditions, the best heat treatment process is 850 ℃×30 min preheating+1160 ℃×30 min quenching+(-65 ℃×1 h) subzero treatment+560 ℃×2 h tempering for 3 times.

Key words: M2 high speed steel, quenching, tempering, subzero treatment, microstructure, mechanical properties

CLC Number: