Heat Treatment of Metals ›› 2023, Vol. 48 ›› Issue (9): 1-7.DOI: 10.13251/j.issn.0254-6051.2023.09.001

• PROCESS RESEARCH •     Next Articles

Heat treatment for toughening technology of cold working die steel SKD11

Yuan Zhizhong1, Wang Mengfei1, Zhang Bocheng1,2, Duan Xubin1, Li Biaomin1, Yang Haifeng1, Luo Rui1, Cheng Xiaonong1   

  1. 1. School of Materials Science and Engineering, Jiangsu University, Zhenjiang Jiangsu 212013, China;
    2. Jingkou Heat Treatment Service Station, Zhenjiang Jiangsu 212012, China
  • Received:2023-03-11 Revised:2023-07-15 Online:2023-09-25 Published:2023-10-25

Abstract: SKD11 steel plate after hot rolling and spheroidizing annealing was used. Two kinds of complex phase heat treatment processes, A-Q-A (Austempering-Quenching-Austempering) and Q-T-A (Quenching-Tempering-Austempering), as well asconventional Q-T(Quenching-Tempering) heat treatment process were carried out.The effect of heat treatment process on the microstructure, hardness and impact absorbed energy was studied. The results show that the microstructure of the specimens after A-Q-A and Q-T-A is the combination of lower bainite (LB) and martensite (M). The content of retained austenite is 13.2% and 18.6% for A-Q-A and Q-T-A, respectively. After A-Q-A, Q-T-A and conventional heat treatment Q-T, the hardness of the specimens is 58.5, 58.6 and 60.5 HRC and the impact absorbed energy is 31.3, 27.6 and 15 J, respectively. The excellent combination of strength and toughness of the SKD11 steel plate is realized by the duplex-phase heat treatments, which does a beneficial exploration in improving the toughness of the cold working die steel.

Key words: SKD11 steel, duplex phase heat treatment, microstructure, impact property, retained austenite

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