CAS-OB精炼和连铸过程钢中夹杂物来源示踪研究

Tracer Research on Source of Inclusions in Steel From CAS-OB Refining and Continuous Casting Process

通过添加示踪剂研究CAS-OB的精炼过程和连铸过程以及板坯钢样夹杂物来源。结果表明,精炼过程和钙处理后的钢中显微夹杂物均含有钢包渣示踪元素镧;中间包钢样中的显微夹杂物同时含有镧和中间包示踪元素铈;板坯中的显微夹杂物含有镧、铈、钾、钠中的几种,说明钢液脱氧产物与钢包渣、中间包覆盖剂、结晶器保护渣均产生了反应。板坯中大型夹杂物主要源于结晶器保护渣,其次源于钢包渣,少部分源于中间包覆盖剂;大型夹杂物同时含有钾、钠、镧、铈中的几种元素,说明大型夹杂物是脱氧产物与卷入钢液中的钢包渣、中间包覆盖剂、保护渣或中间包内衬蚀损产物相互反应的复杂夹杂物。

The sources of inclusions in steel during the CAS-OB refining and slab continuous casting process were investigated by means of tracer method. Results show that the micro-inclusions in steel both in the refining process and after calcium treatment include La which is the tracer in ladle slag. Micro-inclusions in steel from tundish include both La and Ce which is the tracer in tundish flux. Micro-inclusions in slab include part of La, Ce, K and Na. The reason is that the deoxidization products in molten steel react with the ladle slag, tundish flux and mould flux. The macro-inclusions in slab are mainly from the mould flux, and secondly from the ladle slag, and less from tundish flux. Macro-inclusions include trace elements of La, Ce, K and Na simultaneously. Macro-lnclusions are composite inclusion of deoxidization products with the ladle slag, tundish flux and mould flux entangled into the molten steel.