罩型环流机械真空精炼装置脱碳实践

Decarbonization practice of cover-type circulating machinery vacuum refining device

敬业钢铁有限公司新建一台罩型环流机械真空精炼设备,生产无取向硅钢和工业纯铁等超低碳品种钢,控制环节上从转炉碳温协调出钢、制定罩型环流机械真空精炼装置的脱碳工艺、控制原材料碳含量等方面入手,冶炼出w(C)≤20×10-6的工业纯铁等超低碳钢。结果表明:超低碳钢生产过程中,转炉出钢碳质量分数要控制在0.025%~0.040%,采用真空吹氧的条件下转炉出钢碳质量分数可以放宽到0.060%以下,且转炉终点要注意碳温协调出钢,出钢过程严禁加含铝或硅的脱氧合金;真空脱碳需要分段控制脱碳期真空度和钢包底吹驱动气体流量。为防止钢液增碳,应采用碳含量低的合金和耐材。

A new cover-type circulating mechanical vacuum refining equipment has been built in Jingye Iron and Steel Co.,Ltd.to produce ultra-low carbon steels,such as non-oriented silicon steel and industrial pure iron.In the control link,ultra-low carbon steels such as industrial pure iron of w(C)≤20×10-6were smelted from aspects of carbon temperature coordination in converter tapping,development of decarbonization process of cover-type circulating mechanical vacuum refining device and control of carbon content of raw materials.The results showed that in the production process of ultra-low carbon steel,the carbon content of converter tapping should be controlled between 0.025%to 0.040%.Under the condition of vacuum oxygen blowing,the carbon content of converter tapping could be relaxed to less than 0.060%.Carbon and temperature should be coordinated at the end of converter tapping,and deoxidizing alloys containing aluminium or silicon should be strictly prohibited during tapping.Vacuum decarburization needed to control vacuum degree in decarburization period and gas flow driven by bottom blowing of steel ladle in stages.The carbon content of alloys and refractory materials used should be as low as possible.