Q460C高强钢板折弯开裂原因分析

Cause analysis of bending cracking of Q460C high strength steel plate

Q460C高强钢工件在折弯过程中出现开裂。对缺陷附近位置进行成分分析、低倍检验、金相分析和扫描电镜分析。结果表明,钢板内存在马氏体偏析带,且夹杂物容易在偏析带上聚集,是造成Q460C高强钢出现折弯开裂的主要原因。可通过优化连铸二冷区电磁搅拌工艺、延长铸坯堆垛缓冷时间、延长铸坯加热时间等措施,降低折弯开裂出现的概率。

Q460C high strength steel workpiece cracked during bending.The position near defect was analyzed by composition analysis,low magnification inspection,metallographic analysis and scanning electron microscope.Results show that there is martensite segregation zone in steel plate and inclusions gather on segregation zone,which is the main reason for bending cracking of Q460C high strength steel.The bending cracking can be avoided by optimizing electromagnetic stirring process in secondary cooling zone of continuous casting,prolonging stacking slow cooling time and heating time of billet.