轴承钢中间包首炉大型夹杂物分析及控制  

Analysis and control of macro-inclusion of bearing steel in tundish first heat

作　　者：李永超 卢彩玲 左健成 白瑞娟[1,2] 王维 韩怀宾 LI Yong-chao;LU Cai-ling;ZUO Jian-cheng;BAI Rui-juan;WANG Wei;HAN Huai-bin(Technical Centre,Henan Jiyuan Iron and Steel Group Co.,Ltd.,Jiyuan 454650,Henan,China;Technical Centre,Henan Special Steel Advance Material Research Institute Co.,Ltd.,Jiyuan 454650,Henan,China)

机构地区：[1]河南济源钢铁(集团)有限公司技术中心,河南济源454650 [2]河南省特殊钢材料研究院有限公司技术中心,河南济源454650

出　　处：《连铸》2021年第3期35-39,44,共6页Continuous Casting

摘　　要：为实现轴承钢洁净度的快速分析,采用高频水浸超声探伤中间包不同炉次的大型夹杂物情况,发现中间包首炉大型夹杂物超标严重。通过定位解剖后的电镜分析,可知大型夹杂物主要成分为铝酸钙类夹杂物。结合某厂轴承钢生产实际,分析确定中间包首炉大型夹杂物的主要来源为钢液二次氧化产物粘附在水口内壁,促进钢水中原有的铝酸钙类夹杂物沉积,最终水口结瘤物脱落导致。通过控制中间包烘烤温度、减少中间包内钢液二次氧化、采用旋流四孔水口,有效提高了中间包首炉的洁净度,水浸超声探伤结果表明,中间包首炉洁净度值(缺陷总长度/测试体积)由之前的170.4降至12.0mm/dm^(3)。In order to realize the rapid analysis of the cleanliness of bearing steel,the macro-inclusion in different heats of tundish was detected by high-frequency immersion ultrasonic testing.The results show that the macroinclusion in tundish first heat severely exceed the limit.The major components of the macro-inclusion was calcium aluminate type inclusions by scanning election microscopy after locate sawing.According to the production practice of bearing steel in a certain factory,the main source of macro-inclusion is reoxidation of molten steel and its product adhesion to the nozzle inner wall,which promotes the deposition of the original calcium aluminate type inclusions in the molten steel,finally the clogging drop into the molten steel.By optimizing baking temperature of tundish,decreasing reoxidation of molten steel,applying four-port swirling nozzle,the cleanliness value of tundish first heat was significantly decrease.The water immersion ultrasonic inspection results showed that the cleanliness value(total defect length/test volume)of tundish first heat was reduced from 170.4 to 12.0 mm/dm^(3).

关 键 词：中间包首炉 大型夹杂物 中间包烘烤 二次氧化 旋流水口 

分 类 号：TF777[冶金工程—钢铁冶金]