发动机曲轴开裂原因分析  

Analysis on Cause of Engine Crankshaft Cracking

作　　者：陈启略 贺新星 陆杰实 CHEN Qilue;HE Xinxing;LU Jieshi(SAIC-GM-Wuling Automobile Co.,Ltd.,Liuzhou 545007,Guangxi China)

机构地区：[1]上汽通用五菱汽车股份有限公司,广西柳州545007

出　　处：《热处理》2022年第1期46-49,共4页Heat Treatment

摘　　要：某公司汽车发动机SAE1538MV钢曲轴磨削后经磁粉探伤发现连杆颈有裂纹。对开裂的曲轴进行了宏观分析、化学成分分析、力学性能测定、金相检验、表面淬火宽度和深度检测,以查明其开裂的原因。结果表明:该曲轴的化学成分、淬火宽度均符合要求,但有异常铁素条带,淬火深度是要求值的3倍,说明曲轴开裂是锻造和表面淬火工艺不当造成的。The crankshafts of an automotive engine,made of SAE1538MV steel,were found to have crack in their connecting rod neck during magnetic particle inspection after grinding in a company.The cracked crankshaft was subjected to macro-check,chemical composition analysis,mechanical property measurements,metallographic examination,and detection of width and depth of surface hardening,to find out the cause of their cracking.The results showed that the crankshaft exhibited desired chemical composition and hardening width but abnormal banded ferrite and hardening depth which was three times the required value,indicating that the cracking of crankshafts stemmed from fault in both forging process and surface hardening process.

关 键 词：曲轴 铁素条带 淬火裂纹 锻造缺陷 

分 类 号：TG115[金属学及工艺—物理冶金]