对45CrNiMoVA钢采用不同温度淬火且相同回火温度进行了热处理，测定了其常规力学性能和断裂力学性能，并用扫描电镜观察了其断口形貌，以分析淬火温度对其影响的机理。结果表明，在一定范围内淬火温度对45CrNiMoVA钢的屈服强度、抗拉强度和硬度没有影响，而对其断面收缩率、伸长率和冲击功却影响很大，在1 350 ℃淬火下处理将导致材料抗拉强度下降。

Conventional mechanical property and fracture toughness of the 45CrNiMoVA steel conducted by different quenching and equal temper temperature were studied.The mechanism of the quenching temperature affected on its properties were analysed by surveying mechanical properties and fracture toughness and by viewing fracture surface under scanning electron microscope. It was shown that the quenching temperature has not any effect on 45CrNiMoVA steel yield and tensile strength and hardness in definite temperature,but the material fracture face contraction and elongation rate and impact work is very sensitivity to quenching temperature,1350 ℃ quenching may make tensile strength drop.