Q235B钢板折弯开裂原因分析与控制措施

Analysis of bending cracking of Q235B steel plate and control measures

针对用户在使用某厂生产的Q235B热轧卷进行折弯开裂试验时出现的大量开裂问题,借助光学显微镜、扫描电镜和能谱仪等检测方法,对钢板开裂部位和非开裂部位进行了对比分析。分析结果发现材料中存在有明显的夹杂物诱发裂纹的产生,且材料中硫化锰夹杂含量高。通过现场工艺的调整,控制硫化锰夹杂后,可以显著改善折弯开裂问题,避免了此类问题的再次发生。

The problem of serious cracking was observed during bending test of Q235B hot-rolled coil produced by one factory.The cracking position and non-cracking position of steel plate were compared and analyzed by means of optical microscope,scanning electron microscope and energy disperse spectroscopy.The results showed that there were obvious inclusions in the material,which could induce the formation of cracks.Moreover,the content of manganese sulfide inclusions in the material was high.After adjusting the production process and controlling the content of manganese sulfide inclusions,the problem of bending cracking could be significantly improved.The recurrence of this problem was avoided.