耐久道路试验中钢支架断裂原因分析  

Analysis on Fracture Reasons of the Steel Bracket in the Durability Road Test

作　　者：李迎超[1] 刘鹏鹏[1] 岳宗豪[1] 石海琳[1] LI Yingchao LIU Pengpeng YUE Zonghao SHI Hailin(Pan Asia Technical Automotive Center, Shanghai 201201, China)

机构地区：[1]泛亚汽车技术中心有限公司,上海201201

出　　处：《理化检验（物理分册）》2017年第5期353-356,共4页Physical Testing and Chemical Analysis(Part A:Physical Testing)

摘　　要：某汽车用钢支架,在耐久道路试验过程中发生断裂失效。通过化学成分分析、静拉伸试验、金相检验和断口分析,对比了耐久道路试验的失效件和合格件,分析了该钢支架的断裂原因。结果表明:失效支架材料中的碳含量很低,材料的晶界强度较弱;支架断裂部位发生了较大冲压形变,导致应力较大;二次加工脆性是支架沿晶疲劳断裂的根本原因。A steel bracket used in a vehicle fractured during the durability road test.The failure part and the qualified part in the durability test were compared,and the fracture reasons were analyzed by chemical composition analysis,static tensile test,metallographic examination and fracture analysis.The results show that：the carbon content in the material of the failure bracket was extra low,and grain-boundary strength of the material was weak;the large pressing deformation happened to the fracture position of the bracket,which led to the large stress;secondary working embrittlement was the root reason of the intergranular fracture failure of the bracket.

关 键 词：支架 耐久道路试验 疲劳断裂 碳含量 二次加工脆性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]