疲劳性能不合格的38Si7弹簧钢夹杂物分析  

Analysis of the Inclusions in 38Si7 Spring Steel With Fatigue Failure

作　　者：张宏亮[1] 冯光宏[1] 贾志立[1] 

机构地区：[1]钢铁研究总院冶金工艺研究所,北京100081

出　　处：《钢铁》2011年第5期85-88,共4页Iron and Steel

摘　　要：针对工业生产38Si7弹簧钢疲劳强度不合格的问题,借助光学显微镜和扫描电镜,并结合数学理论模型,从夹杂物的角度分析38Si7弹簧钢疲劳强度不合格的原因。研究结果表明:工业生产38Si7弹簧钢中的夹杂物主要组成为CaO(MgO)-Al2O3-SiO2三元复合夹杂物,而且圆截面上中心区域复合夹杂物中Al2O3的含量明显低于外层复合夹杂物中Al2O3的含量;根据夹杂物等效投影面积模型得出,当疲劳失效为内部起裂时,临界夹杂物尺寸大约为6.5μm,当疲劳失效为表面起裂时,临界夹杂物尺寸大约为5.5μm。当弹簧钢中的夹杂物尺寸大于临界夹杂物尺寸时,容易造成疲劳强度失效。In view of the 38Si7 spring steel of industrial production with fatigue failure,using optical microscopy and scanning electron microscopy,combined with mathematical theoretical models,the reason of 38Si7 spring steel with fatigue failure was analyzed from the perspective of inclusion.The results show that the inclusions in 38Si7 spring steel of industrial production is mainly composed of CaO（MgO）-Al2O3-SiO2 ternary complex inclusions,and the Al2O3 composite contents of complex inclusion in the central region of round cross section are significantly lower than the outer layer.According to the projected area equivalent inclusion model,when the fatigue failure is from an internal crack,the critical inclusion size is approximately 6.5μm;when the fatigue failure is from the surface crack,the critical inclusion size is approximately 5.5μm.When the inclusion size in the spring steel is larger than the critical size of inclusions,the probability of fatigue failure will increase.

关 键 词：弹簧钢 疲劳失效 临界夹杂物尺寸 

分 类 号：TG142.13[一般工业技术—材料科学与工程]