某车型半轴断裂失效分析  

Failure Analysis of Half Shaft of Vehicle

作　　者：苏安喜 宋文强 向冤梅 吴锡华 曾桂莲 何万珣 Su Anxi;Song Wenqiang;Xiang Yuanmei;Wu Xihua;Zeng Guilian;He Wanxun

机构地区：[1]上汽通用五菱汽车股份有限公司,广西柳州市545007

出　　处：《时代汽车》2023年第4期162-164,共3页Auto Time

摘　　要：汽车半轴是汽车驱动桥结构中非常重要的部件,起着动力传递、改变转速联结的重要作用,如果出现断裂失效会导致非常严重的后果。针对某车型开发试验中半轴在极限保压试验过程中发生断裂的问题,通过宏观断口分析、微观断口分析、硬度检测、金相分析查找出了导致半轴断裂的原因。分析结果表明:断口为韧性断口,微观形貌为沿晶断裂和韧窝形貌,显微组织外圈为回火马氏体,心部组织为珠光体和铁素体,主要断裂原因是半轴受外力扭转过载导致断裂失效。另外,芯部存在带状组织和网块状铁素体,在一定程度上降低了晶界的结合强度,促进了半轴的断裂。带状组织可能是铸造过程中合金偏析造成的,且未经过正火消除。网块状铁素体可能是半轴在热处理时淬火温度过高或保温时间过短或冷却速度过快形成的。Half Shaft is a very important part of the vehicle drive axle,which plays an important role in power transmission and changing the speed connection.If fracture failure,it will lead to very serious consequences.Aiming at the problem that the half-shaft fracture occurred in the process of the ultimate pressure holding test in the development test of a certain vehicle model,the cause of the half-shaft fracture was found out through the Macroscopic fracture analysis,Microscopic fracture analysis,hardness detection and metallographic analysis analysis.The results show that the fracture is ductile,the microstructure is intergranular fracture and dimplex morphology,the outside of microstructure is tempered martensite,and the inside microstructure is pearlite and ferrite.The main reason for the fracture failure is torsional overload caused by external force on the half-axis.In addition,There are banded structures and massive ferrites in the interior,It reduces the binding strength of grain boundaries to a certain extent and promotes the fracture of the semiaxis.The banded structure may be caused by alloy segregation in the casting process,and it has not been normalized.The bulk ferrite may be formed by high quenching temperature or short holding time or too fast cooling rate during heat treatment.

关 键 词：汽车半轴 断口分析 金相分析 

分 类 号：TG1[金属学及工艺—金属学]