Heat Treatment of Metals ›› 2022, Vol. 47 ›› Issue (5): 71-75.DOI: 10.13251/j.issn.0254-6051.2022.05.011

• MATERIALS RESEARCH • Previous Articles     Next Articles

Phase transformation law of H13 steel and numerical simulation of vacuum heat treatment for dies

Guo Shuo, Fan Zhenyu, Wang Huizhen, Zhou Leyu, Zhai Yuewen   

  1. Beijing Research Institute of Mechanical and Electrical Technology Ltd., Beijing 100083, China
  • Received:2022-01-06 Revised:2022-03-07 Online:2022-05-25 Published:2022-06-16

Abstract: Aiming at numerical simulation for microstructure evolution predicting of H13 hot work steel dies in vacuum quenching heat treatment, continuous cooling phase transformation tests were performed on the H13 steel by using DIL805L thermal dilatometer, and the continuous cooling transformation curve (CCT curve) of the H13 steel was plotted by combining microstructure and hardness results. The effect of different cooling rate on microstructure and hardness of the specimens was studied, and the phase transformation factors in the Koistinen-Marburger equation were fitted to investigate the phase transformation law of the H13 steel. The results show that the critical cooling rate of martensite transformation is 1 ℃/s, the Ms point is 335 ℃, and with the increase of cooling rate, the hardness of the specimen increases to 660 HV. By importing the fitted martensitic phase transformation equation into finite element software by secondary development means to carry out numerical simulation calculation, the results show that the volume fraction of martensite at different sampling points of H13 steel die is 90%. It can be considered that the microstructure of H13 steel die after vacuum gas quenching is martensite and retained austenite.

Key words: H13 steel, CCT curve, Koistinen-Marburger equation, numerical simulation

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