热轧带钢孔洞缺陷的形成原因与控制措施  

Formation mechanism and controlling of hole defects in hot-rolled strip

作　　者：金柱元 李亮[1] 朱志强 晏武 赵斌 JIN Zhuyuan;LI Liang;ZHU Zhiqiang;YAN Wu;ZHAO Bin(Department of Iron and Steel Research and Development,Rizhao Steel Holding Group Co.,Ltd.,Rizhao 276800,Shandong,China)

机构地区：[1]日照钢铁控股集团有限公司,山东日照276800

出　　处：《四川冶金》2022年第5期46-49,54,共5页Sichuan Metallurgy

摘　　要：应用生产工艺数据统计分析、扫描电镜、能谱分析以及化学成分分析等方法,系统研究了热轧带钢孔洞缺陷的形成原因。结果表明:孔洞缺陷主要由连铸浸入式水口内壁结瘤物脱落并在结晶器中未上浮而被凝固坯壳捕获的大型夹杂物引起的,该类夹杂物主要为未被充分钙处理的脱氧产物;此外还有少量含有引流砂和结晶器保护渣成分的大型夹杂物。本文提出了提高Ca处理深度、优化中间包流场、提高控制连铸过程二次氧化的能力、减少结晶器液面波动等控制措施。综合措施的应用效果表明,大型夹杂物数量得到大幅下降,由大型夹杂物导致的孔洞缺陷率平均4.7个/t下降至1.0个/t,下降比例达79%。The formation reasons for the hole defects in the hot-rolled strip were studied systematically by means of statistical analysis of production process data,scanning electron microscopy(SEM),energy dispersion spectrum analysis(EDS),and chemical composition analysis.The results show that the hole defects are mainly caused by the large-sized inclusions trapped into the solidified shell due to falling off the clogging on the inner wall of the submerged nozzle and not floating up in the mold,which are mainly the deoxidized products not fully treated by calcium.In addition,there are a small number of large inclusions containing stuffing sand and mold slag.Some countermeasures were put forward,such as increasing Ca treatment level,optimizing the flow field in tundish,improving the ability to control the reoxidation of the continuous casting process,and reducing mold level fluctuation.The application results of the countermeasures show that the number of large inclusions has been greatly reduced,and the number of hole defects caused by large inclusions has decreased from 4.7/t to 1.0/t on average,reduce proportion up to 79%.

关 键 词：孔洞缺陷 浸入式水口 水口结瘤 大型夹杂物 钙处理 

分 类 号：TF769.2[冶金工程—钢铁冶金]