热镀锌IF钢表面线状缺陷形成原因分析  

Analysis of Linear Defects on Hot-dip Galvanized IF Steel Surface

作　　者：刘小斐[1,2] 赵顺利 盖彦青 Liu Xiaofei;Zhao Shunli;Gai Yanqing(Erdos Vocational College,Erdos 017000,Inner Mongolia,China;Baosteel Central Research Institute,Shanghai 201900,China)

机构地区：[1]鄂尔多斯职业学院,内蒙古鄂尔多斯017000 [2]宝钢中央研究院,上海201900

出　　处：《钢铁钒钛》2019年第3期152-157,共6页Iron Steel Vanadium Titanium

摘　　要：采用扫描电镜及金相等分析方法对热镀锌板及同批次生产热轧板表面单长线及双棱线缺陷进行了微观组织分析,结果表明,板坯在连铸浇注过程中结晶器液位波动造成保护渣卷入是此类缺陷发生的根本原因。通过降低连铸拉速以及适当增加浸入式水口插入深度,将结晶器液面波动控制在±3mm以内能有效控制保护渣卷入。同时,对连铸过程中液面波动超过±5mm板坯进行表面火焰清理,可大幅降低此类缺陷发生率。The microstructure of single-long line and double-edged line defects on the surface of hot-dip galvanized sheets and hot-rolled sheets produced in the same time were analyzed by means of scanning electron microscope (SEM) and metallography.The results show that the entrapment of protective slag caused by crystallizer level fluctuation during continuous casting is the fundamental cause of such defects.By reducing the casting speed and increasing the insertion depth of the submerged nozzle properly,the slag entrapment can be effectively controlled by controlling the fluctuation of the liquid level within ±3 mm.At the same time,surface flame cleaning was used to handle those slabs with liquid level fluctuation exceeding ±5 mm during continuous casting.The occurrence rate of such edge linear defects can be greatly reduced.

关 键 词：热镀锌板 长线缺陷 双棱线缺陷 卷渣 

分 类 号：TF76[冶金工程—钢铁冶金] TG174.44[金属学及工艺—金属表面处理]