J. Mater. Sci. Technol. ›› 2023, Vol. 136: 212-222.DOI: 10.1016/j.jmst.2022.07.030

• Research Article • Previous Articles     Next Articles

A model for converting thermal analysis to volume fraction of high carbon bearing steels during low-temperature tempering

Qinglong Liua,c, Junyu Tiana, Wenting Weib,c,d,*   

  1. aThe State Key Laboratory of Refractories and Metallurgy, The Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan 430081, China;
    bSchool of Automotive Engineering, Wuhan University of Technology, Wuhan 430070, China;
    cHubei Key Laboratory of Advanced Technology for Automotive Components (Wuhan University of Technology), Wuhan 430070, China;
    dHubei Collaborative Innovation Center for Automotive Components Technology, Wuhan 430070, China
  • Received:2022-05-09 Revised:2022-07-12 Accepted:2022-07-15 Published:2023-02-10 Online:2022-08-28
  • Contact: * E-mail address: wei_wt@whut.edu.cn (W. Wei).
  • About author:1 These authors contributed equally to this work.

Abstract: Quantitative prediction of phase content is of great importance to control and optimize the heat treatment process of steels. In this work, a model for predicting the phase content of tempered high carbon steels was proposed by taking a martensitic 100Cr6 bearing steel as a model case. The microstructural transformations during tempering were studied using thermal analysis, transmission electron microscopy (TEM), and X-ray diffraction (XRD). Kinetics analysis of thermal evolution by employing the isoconversional method, and assisted by TEM and XRD characterization, were performed to quantitatively estimate the volume fractions of different phases after tempering. A series of isothermal tempering experiments were designed to verify the model. The predicted results were in good agreement with the experimental results of XRD and electrolytic extraction measurements.

Key words: Bearing steel, Martensite tempering, Retained austenite, Thermal analysis, Kinetics