冷作模具钢SKD11的热处理增韧技术

Heat treatment for toughening technology of cold working die steel SKD11

选用热轧和球化退火后的SKD11钢板,对其进行A-Q-A(Austempering-Quenching-Austempering)、Q-T-A(Quenching-Tempering-Austempering)两种复相热处理工艺以及Q-T(Quenching-Tempering)常规热处理工艺,研究不同热处理工艺对钢板微观组织、硬度和冲击吸收能量的影响。结果表明:A-Q-A和Q-T-A热处理试样的组织均为下贝氏体(LB)和马氏体(M)的复相组织,并且残留奥氏体(RA)的含量分别为13.2%和18.6%。经A-Q-A、Q-T-A和常规热处理Q-T后,试样的硬度分别为58.5、58.6和60.5 HRC,冲击吸收能量分别为31.3、27.6和15 J。复相处理的工艺实现了SKD11钢板优异的强韧性配合,为提升冷作模具钢的韧性进行了有益的探索。

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.