150 mm×150 mm小方坯超低碳钢H1T生产实践

Production Practice of Ultra-Low Carbon Steel H1T in 150 mm×150 mm Small Billet

针对超低碳钢H1T传统的预处理-转炉-RH-大方坯连铸/模铸-开坯工艺生产成本高,以及连铸浇注过程中容易发生堵塞水口导致生产中断的问题,开发了150 mm×150 mm方坯连铸生产工艺,重点针对连铸水口结瘤堵塞进行工艺控制,并对生产过程中化学成分、渣系、夹杂物变化进行分析。工业生产表明,采用转炉出钢加铝脱氧、LF渣碱度>10,顶渣(FeO+MnO)≤2%,搅拌氩气流量>600 L/min确保脱硫、RH工序在65 Pa以下吹氧深脱碳、钢水钙处理等工艺优化,成功生产出超低碳钢H1T产品,并且连浇炉数达到10炉次。

In order to solve the problems of high blooming cost of the traditional process route for ultra-low carbon steel H1T,including preprocessing,converter,RH,bloom/ingot continuous casting,and blooming,and the frequent blockage of nozzle in the process of continuous casting which leads to production interruption,a 150 mm×150 mm billet continuous casting production process has been developed.The process control has been focused on the blockage of continuous casting nozzle,and the changes of composition,slag system,and inclusions during the production process have been analyzed.The industrial production practice shows that the product of ultra-low carbon steel H1T has been successfully produced by adopting the process of adding aluminum for deoxidation in converter tapping,LF slag basicity>10,top slag(FeO+MnO)≤2%,stirring argon flow>600 L/min to ensure desulfurization,RH process with oxygen blowing for deep decarburization under 65 Pa,and calcium treatment of molten steel.And the number of continuous heats has reached 10 heats.