淬火工艺参数对40Cr合金钢组织性能的影响

Effects of quenching process parameter on microstructures and properties of 40Cr alloy steel

采用光学显微镜（OM）、电子万能拉伸试验机、冲击试验机等设备和手段,研究了淬火工艺参数对40Cr合金钢调质组织和性能的影响。结果表明,当40Cr合金钢奥氏体化完全、晶粒未粗化的情况下,PAG淬火液浓度是影响其组织和性能的主要因素,PAG淬火液浓度从2.60%升高至3.20%,钢的强度降低,塑性增加;PAG淬火液浓度继续升高至4.00%时,40Cr合金钢中铁素体含量增加,同时下贝氏体含量也增加,其强度增加,塑性降低。当40Cr合金钢淬火温度为870℃、淬火频率为21Hz、PAG淬火液的浓度低于3.20%时,钢中可避免出现铁素体和下贝氏体组织,调质处理时可获得理想的回火索氏体组织。

The microstructure and properties of 40 Cr steel treated by different quenching process parameters were studied by means of optical microscope（OM）,electro-mechanical universal testing machine and shock testing machine.The results show that when the austenitizing of 40 Cr steel was completed and the grain was not coarse-grained,the concentration of PAG quenching liquid is the main factor to influence its microstructure and mechanical properties.With concentration of PAG quenching liquid rising from 2.60%to 3.20%,the steel strength decreasing and the plasticity rising.Then continued to increase the concentration of PAG quenching liquid to 4.00%,the content both ferrite and lower bainite increased in the 40 Cr steel.However,the strength increased a little and the plasticity decreased.When the quenching temperature is 870 ℃,the quenching frequency is 21 Hz and the concentration of PAG quenching solution is less than 3.20%,the ferrite and lower bainite can be avoided and the ideal tempered sorbite can be obtained in 40 Cr steel after quenched and tempered.