研究了等温淬火工艺对机床用球墨铸铁组织和力学性能的影响。结果表明,随着等温淬火温度的提高,球墨铸铁组织中的奥氏体晶粒长大,晶粒形状逐渐从针状转变为羽毛状。随着淬火温度的增加,球墨铸铁抗拉强度降低。球墨铸铁硬度随淬火温度增加而降低,冲击韧度随淬火温度增加而增加。 The effect of austempering process on the microstructure and mechanical properties of ductile iron for machine tools was studied. The results show that as the austempering temperature increases, the austenite grain grows in the ductile cast iron and the grain shape gradually changes from acicular to feathering. As the quenching temperature increases, the tensile strength of ductile iron decreases. Ductile iron hardness decreases with increasing quenching temperature, impact toughness increases with quenching temperature.