回火温度对40CrNiMo7钢组织与性能的影响  

Influence of tempering temperature on microstructure and mechanical properties of 40CrNiMo7 steel

作　　者：李继红[1] 李岩[1,2] 张海存 支金花 张敏[1] 

机构地区：[1]西安理工大学材料科学与工程学院,陕西西安710048 [2]西安陕鼓动力股份有限公司,陕西西安710075

出　　处：《金属热处理》2011年第7期28-31,共4页Heat Treatment of Metals

基　　金：西安市科技计划项目(cxy09024);陕西省教育厅自然科学基金项目(08JK360)

摘　　要：通过显微组织观察、拉伸和冲击试验、硬度测试、冲击断口分析等研究了回火温度对40CrNiMo7钢组织与性能的影响。结果表明,40CrNiMo7钢经850℃油淬400~700℃回火后的组织均为回火索氏体＋马氏体＋碳化物;650℃回火时实现了优良的强韧性匹配;400℃回火时常温强度达到最大,冲击吸收能量则最低,而700℃回火时则反之;随着回火温度的升高,40CrNiMo7钢的硬度逐渐减小。随着试验温度的降低,试验钢强度逐渐升高韧性却逐渐降低,而断后伸长率和断面收缩率基本没有变化。The effects of tempering temperature on microstructure and mechanical properties of 40CrNiMo7 steel were investigated by using microstructure observation,stretching and impact test,hardness testing and impact fracture analysis.The results show that the microstructure of 40CrNiMo7 steel tempered at 400-700 ℃ after oil quenching at 850 ℃ is composed of tempered sorbite,martensite and carbides.40CrNiMo7 steel has the perfect combination of strength and toughness after tempering at 650 ℃,the room temperature strength is maximum and impact energy is minimum at 400 ℃,and at 700 ℃ the results are quite the opposite.With increasing of tempering temperature,the hardness of 40CrNiMo7 steel is reduced.And the strength increases with decreasing of test temperature,and the impact toughness lowers simultaneously.However,test temperature has no significantly influence on elongation and reduction of area.

关 键 词：40CrNiMo7钢 回火索氏体 马氏体 回火温度 

分 类 号：TG113.12[金属学及工艺—物理冶金] TG113.25[金属学及工艺—金属学]