一步等温淬火温度对高强韧ADI组织与性能的影响

Effect of one step austempering temperature on microstructure and mechanical properties of high strength and ductility ADI

对不同一步等温淬火温度下球墨铸铁的显微组织、力学性能、X射线衍射、断口形貌进行了分析,研究了一步等温淬火温度对高强韧等温淬火球墨铸铁(ADI)组织和性能的影响。结果表明:一步等温淬火最佳温度为280℃,在此温度下等温淬火,得到的基体组织为细小的针状铁素体和残留奥氏体,此时基体中残留奥氏体分布均匀,含量为19.9%,ADI的各项性能达到最优:抗拉强度为1320 MPa、屈服强度1230 MPa、硬度372 HBW、伸长率13%和冲击吸收能量82.5 J。

Microstructure,mechanical properties,X-ray diffraction and fracture morphology of austempered ductile iron（ ADI） under different one step austempering temperature were analyzed. Effect of one step austempering temperature on microstructure and mechanical properties was studied. The results show that the best one step austempering temperature is 280 ℃, isothermal quenching at this temperature,matrix microstructure consist of fine acicular ferrite and retained austenite,in this case the retained austenite uniformly distributed whose content reaches 19. 9%,meanwhile,the ADI reaches the best properties,with tensile strength 1320 MPa,yield strength1230 MPa,hardness 372 HBW,elongation 13% and impact absorbed energy 82. 5 J.