汽车驻车棘爪断裂原因分析  

Cause Analysis of Fracture of Car Parking Pawl

作　　者：张学彬 赵静波 廖振华 葛伟杰 程晓寅 ZHANG Xuebin;ZHAO Jingbo;LIAO Zhenhua;GE Weijie;CHENG Xiaoyin(Ningbo Academy of Product and Food Quality Inspection(Ningbo Fibre Inspection Institute),Ningbo 315048,China)

机构地区：[1]宁波市产品食品质量检验研究院(宁波市纤维检验所),浙江宁波315048

出　　处：《热加工工艺》2023年第22期128-130,共3页Hot Working Technology

摘　　要：采用化学成分分析、断口分析、硬度测试及金相分析等方法,对汽车驻车棘爪的断裂进行了检验和原因分析。结果表明:该驻车棘爪的断裂属脆性断裂,其主要原因是其渗碳淬火层存在表层内氧化,导致其在工作应力作用下在应力薄弱的棘爪圆弧过渡处产生裂纹;其材料晶粒严重不均匀,个别晶粒异常粗大,导致渗碳淬火后形成粗大马氏体,增大材料脆性,产生脆性断裂。By means of chemical composition analysis,fracture analysis,hardness test and metallographic analysis,the fracture causes of a car parking pawl were examined and analyzed.The results show that,the fracture of the pawl belongs to brittle fracture,the main reason is that the surface layer in the carburizing and quenching layer is oxidized,which leads to the crack at the arc transition of the pawl with weak stress under the action of working stress.The grain size of the material is very uneven and individual grain is unusually coarse,which leads to the formation of coarse martensite after carburizing and quenching.It increases the brittleness of the material and leads to brittle fracture.

关 键 词：驻车棘爪 渗碳淬火 断裂 内氧化 

分 类 号：TG111.91[金属学及工艺—物理冶金] TG161[金属学及工艺—金属学]