热轧带钢边部结疤缺陷分析及控制

Analysis and control of hot rolled strip edge scarring

针对武汉钢铁有限公司热轧厂带钢边部结疤问题,通过带钢表面检测数据统计,结合实物缺陷宏观形貌观察,将边部结疤分为蝌蚪状结疤、折叠状结疤、坑状结疤及条状结疤4类;对各类结疤取样后进行金相显微观察和扫描电镜分析,并结合炼钢、热轧生产工艺调查分析,找出了各类结疤的产生原因。通过采取热轧精轧侧导板控制、连铸二次冷却工艺优化、铸坯火焰清理控制及结晶器精度控制等措施,将热轧带钢边部结疤发生率由15.2%降低到0.29%。

For the strip edge scarring of hot rolling mill in Wuhan Iron Steel CO.,Ltd.,through the data statistics for surface inspection combined with macroscopic morphology observation of the actual defects,the edge scarring was classified as four sorts of tadpole shape,fold shape,pit shape and strip shape.By metallographic and scanning electron microscope analysis for each type of scarring samples,combining with investigation and analysis of steelmaking and hot rolling production process,the causes of each type of scarring were found.By the measures of hot rolling finishing side guide control,process optimization for continuous casting secondary cooling,cast billet flame cleaning control,mold precision control,incidence rate of hot strip edge scarring decreased from 15.2 %to 0.29 %.