淬火介质对42CrMo钢棒淬火组织及硬度影响的数值模拟及试验验证

基于有限元计算分析了直径为ø40 mm的42CrMo钢圆棒试样分别使用淬火油和PAG水基液淬火后试样不同位置的组织、硬度以及淬火过程中的温度变化,采用硬度检测和显微组织分析对模拟结果进行了验证。结果表明,当使用淬火油淬火时,试样表面由奥氏体向马氏体和贝氏体转变,心部由奥氏体向贝氏体转变;当使用PAG水基液淬火时,试样表层几乎转变成马氏体,心部转变成马氏体和贝氏体;试样经淬火油和PAG水基液淬火后,表面硬度分别为58和55 HRC,均由表面至心部硬度逐渐降低,但使用PAG水基液淬火后试样的心部硬度比用淬火油的高5 HRC,约为50 HRC。

Numerical simulation and experimental verification of effect of quenching medium on quenching microstructure and hardness of 42CrMo steel rod

Based on finite element method,the microstructure,hardness and temperature changes at various positions of Φ40 mm 42 CrMo steel round rod specimens were analyzed when the specimens quenched by quenching oil and PAG aqueous solution respectively,and the simulation results were verified by hardness test and microstructure analysis. The results show that the surface microstructure of the specimens changes from austenite to martensite and bainite,and the core microstructure changes from austenite to bainite. Using PAG aqueous solution quenching,the surface microstructure of the specimen is almost transformed into martensite,and the core into martensite and bainite. After quenching by quenching oil and PAG aqueous solution,the surface hardness of the specimens is 58 and 55 HRC respectively,and the hardness decreases gradually from the surface to the core. After quenching by PAG aqueous solution,the hardness of the specimen is about 50 HRC,which is 5 HRC higher than that by quenching oil.