Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (2): 130-135.DOI: 10.13251/j.issn.0254-6051.2021.02.022

• PROCESS RESEARCH • Previous Articles     Next Articles

Effect of solution pretreatment after forging on annealed microstructure and impact property of H13 steel

Sun Liguo1, Zhou Jian2, Ma Dangshen2, Chi Hongxiao2   

  1. 1. Fushun Special Steel Co., Ltd., Fushun Liaoning 113001, China;
    2. Special Steels Research Institute, Central Iron & Steel Research Institute, Beijing 100081, China
  • Received:2020-07-29 Online:2021-02-25 Published:2021-05-08

Abstract: Effects of different solution pretreatment and isothermal spheroidizing on the microstructure and impact property of H13 hot work die steel were studied by means of phase analysis, SEM, TEM, and equilibrium phase diagram of the H13 steel was calculated by Thermo-Calc software. The results show that after solution pretreatment at 1000 ℃, 1050 ℃ and 1100 ℃, the quantity of MC type undissolved carbides dominated by V gradually decreases with the increase of solution temperature. After solution pretreatment at 1100 ℃, undissolved carbides are basically dissolved and the grains are coarsened. After solution pretreatment and isothermal spheroidizing, the distribution uniformity and roundness of the carbides are improved, but the grain size is coarsened at 1100 ℃, and a coarse network is formed and nucleated along the coarse martensite interface during the annealing process, which reduces the structure uniformity. The impact property of the H13 steel is better when solution pretreated at 1000 ℃ and then isothermally spheroidized, and with the increase of solution pretreatment temperature, the impact property of the tested steel shows a significant downward trend.

Key words: H13 steel, solution pretreatment, isothermal spheroidizing, MC carbides, impact property

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