【摘要】 分别采取普通等温淬火、两级等温淬火、等温淬火 +回火 3种热处理工艺对较高温度下球墨铸铁 (成分为质量分数 % :3 80C ,2 4 6Si,0 2 5Mn ,0 0 2 6S ,0 0 36P ,0 0 5 1Mg ,0 0 2 2RE)的组织和性能进行了研究 ,发现热处理工艺带变窄或消失 ,得到基体中不含奥氏体的贝氏体球墨铸铁。这种球墨铸铁虽然塑韧性较差 ,但具有较高的强度、硬度和疲劳极限 ,而且耐磨性和切削性良好更多还原

【Abstract】 The paper deals with the structure and properties of 3 80%C,2 46%Si,0 25%Mn,0 026%S,0 036%P,0 051%Mg,0 022%RE ductile cast iron heat treated at higher temperature through conventional austempering,two step austempering or austempering+tempering.It was found that the heat treat processing zone is narrow/disappeared at higher temperature so that the bainitic ductile cast iron without austenite in the matrix can be obtained.The ductile iron has not only high tensile strength and hardness and fatigue limit but also excellent wear resistance and machinability.更多还原