0Cr18Ni9不锈钢中非金属夹杂物来源

Origin of non-metallic inclusions in 0Cr18Ni9 stainless steel

为了研究不锈钢连铸坯中非金属夹杂物的主要类型及其主要来源,用扫描电镜分析了0Cr18Ni9不锈钢连铸坯中的夹杂物成成,并分别在AOD渣、大包渣及中间包渣中加入示踪剂进行了三次示踪实验.实验结果表明,0Cr18Ni9不锈钢连铸坯中的非金属夹杂物主要为CaO-SiO2-Al2O3-MgO系夹杂物,其次为MgO-Al2O3类尖晶石和硫化物;非金属夹杂物的主要来源是AOD还原期的还原产物、脱硫产物和出钢时混入钢水中的AOD渣滴;AOD出钢后,大包顶渣、中间包覆盖剂和结晶器保护渣不会对钢液造成明显污染.

To research the major type of inclusions in stainless steel slabs and find out their primary origin, the composition of the non-metallic inclusions was analyzed by SEM, and three tracer experiments were performed by adding a tracer into AOD slag, ladle slag and tundish slag, respectively. The results show that the primary non-metallic inclusions in 0Cr18Ni9 stainless steel slabs is CaO-SiO2-Al2O3-MgO system inclusions, the second is MgO-Al2O3 spinel and sulphide; the primary origin of the non-metallic inclusions is the production of deoxidation and desulfuration during AOD reducing and the AOD slag suspension in the molten steel during tapping; after tapping, the molten steel is not obviously polluted by ladle slag, tundish covering flux and mold flux.