特厚板连铸保护渣系列规划

Systematization of mold fluxes for ultra-thick slab continuous casting

针对特厚板连铸工艺的特点,分析了传统的中厚板连铸保护渣与特厚板连铸保护渣的作用特征差异。根据不同钢种在结晶器内的凝固特性,对新钢特厚板连铸保护渣进行了系列规划,分为高碳钢连铸保护渣、包晶钢连铸保护渣、中碳低合金钢连铸保护渣3大类。在此基础上,提出了保护渣熔化温度、黏度、转折温度、结晶比例的控制范围。生产实践表明,设计的保护渣浇铸过程结晶器内状况良好,渣面无结团、结块现象,液渣层厚度合适,保护渣消耗量正常,铸坯表面质量优良,连铸生产工艺顺行。

The characteristic differences between traditional mold fluxes for medium or thick slabs continuous casting and ultra-thick slabs continuous casting were analyzed based on the technological characteristics of ultra-thick slabs cast-ing. Then,the systematization of mold fluxes was conducted after the discussion of solidification features of for different grades,and three mold flux groups were proposed：high carbon steels,peritectic steels and micro alloying steels with me-dium carbon content. Based on the classification,the control ranges of melting temperature、viscosity、break temperature and crystallization ratio of mold fluxes were put forward. Commercial production data reveals that with proposed mold fluxes,smooth and stable casting can be obtained and no sintering is observed. The thickness of liquid slag layer and con-sumption are suitable. The surface quality of slabs is perfect and the continuous casting process is smooth.