汽车大梁用500L-Z热轧钢裂纹形成原因分析

Causes Analysis of Crack Formation in Hot Rolled 500L-Z Steel for Automobile Beams

某汽车大梁用500L-Z钢在冲压过程中出现开裂。采用宏观检验、金相检验和扫描电镜检验对其冲压开裂的原因进行了分析。结果表明:在冲压过程中,切边不平直处发生加工硬化导致开裂,而试样中间的珠光体偏析带也是产生裂纹的原因之一。

Cracking of 500 L-Z steel for automobile beam during stamping appears. The causes of cracking during stamping were analyzed by means of macroscopic examination, metallographic examination and scanning electron microscopy(SEM). The results show that during the stamping process, work-hardening occurs at the uneven place of trimming side,resulting in cracking. The pearlite segregation band in the middle of the sample is also one of the reasons for the crack.