厚板包晶钢保护渣的开发与应用  

Development and application of mold flux for heavy plate peritectic steel

作　　者：张晨[1] 蔡得祥[1] 徐国栋[2] 范英同[2] ZHANG Chen;CAI De-xiang;XU Guo-dong;FAN Ying-tong(Research Institute,Baoshan Iron and SteelCo.,Ltd.,Shanghai 201999,China;Steelmaking Plant,Baoshan Iron and Steel Co.,Ltd.,Shanghai 201999,China)

机构地区：[1]宝山钢铁股份有限公司研究院,上海201999 [2]宝山钢铁股份有限公司炼钢厂,上海201999

出　　处：《连铸》2021年第2期51-56,共6页Continuous Casting

摘　　要：针对宝钢3号厚板连铸机改造投产后原保护渣不适应问题,结合铸机工艺特点对包晶钢用保护渣进行了研制开发,提出了一种高黏度、高析晶温度的设计方案,在实验室研究了碱度、Na_(2)O、F等成分组元对析晶温度的影响。结果表明,在所研究的质量分数范围内,降低F质量分数对提高析晶温度是有利的,Na_(2)O质量分数为4%时析晶温度最高,碱度越高,析晶温度也越高。通过降低碱度和F质量分数可实现提高黏度的目标,优化F、Na_(2)O的质量分数以弥补低碱度的不足。先后开发了3种保护渣,稳步提高析晶温度,确保保护渣在试验过程中不至于因润滑功能不足而影响正常的连铸生产。经一年多的生产实践,析晶温度超过1 200℃的包晶钢保护渣完全满足要求。经批量应用,铸坯纵裂发生率年平均值降到了0.26%,达到了预期目标。In view of inapplicability of the initial mold flux after the transformation of No.3 heavy plate continuous caster in Baosteel,new mold flux for peritectic steel with high viscosity and high crystallization temperature was developed in combination with the casting process characteristics.Firstly,the effects of basicity,Na2 O and F on crystallization temperature were studied in the laboratory.The results showed that,within the studied content range,decreasing F was beneficial to increasing crystallization temperature.When Na_(2)O content was 4%,crystallization temperature was the highest,the basicity was higher,and the crystallization temperature was higher.By reducing basicity and F,the viscosity can be improved,F and Na_(2)O can be optimized to make up for the shortage of low basicity.Three kinds of mold flux have been developed successively to steadily increase the crystallization temperature,so as to ensure that the mold flux will not affect the normal continuous casting production due to insufficient lubrication function during the test.After more than one year of production practice,the mold flux for peritectic steel with crystallization temperature exceeds 1 200℃completely meets the requirements.After batch application,the annual average incidence of slab longitudinal crack is reduced to 0.26%,reaching the expected target.

关 键 词：连铸 厚板 包晶钢 保护渣 析晶温度 

分 类 号：TF777[冶金工程—钢铁冶金]