电镀锌板流星状白色亮斑缺陷的研究

低碳钢(w(C)≤0.06%)作为电镀锌基材,在热轧轧制时易发生混晶现象。该缺陷表现为钢板表面电镀锌后,上表面出现流星状白色亮斑缺陷。通过冷轧和热轧原板样的金相检测,判断亮斑缺陷与基板混晶存在关联,且源于热轧工序。并对混晶发生的原因进行了分析,开展了相应的工艺调整试验,确认混晶与热轧FT7、CT目标值设定相关性显著。最终通过对FT7、CT工艺的联合调整,亮斑缺陷得以消除。

Research of the meteor-shape-white-spot defect on electro-galvanized sheet

The low-carbon steel with the mass fraction of C≤0.06 % used for the basic material of electro-galvanized sheet,was easy to occur the phenomenon of mixed grain at the rolling of hot strip mill,which led to the meteor-shape-white-spot defect occurred on the upper surface after the surface of steel sheet was electro galvanized.Through metal-lographic analysis of the hot and cold rolled strip,the results showed that the white-spot defect was associated with the mixed grain of the basic material,which could be from the hot-rolling process.The reason of the mixed grain was analyzed,and the corresponding test of process modification was carried out.It was confirmed that the mixed grain was significantly correlated with FT7、CT target value of hot-rolling process.Finally after the combined adj ustment process of FT7、CT,the white-spot defect was resolved.