SPHC铸坯中大型夹杂物行为

探讨了BOF—LF—CC流程生产的SPHC连铸坯中大型夹杂物的类型、数量、尺寸及分布,并通过示踪剂追踪分析了钢中夹杂物的来源。结果表明：铸坯中大型夹杂物主要的三类复合夹杂物为Al2O3-CaO-MgO-MnS类、CaO-Al2O3类和MgO-CaS类,含量分别为56%、26.8%和17.2%,此外,含Al2O3大型夹杂物约占总数的82.8%。头坯中大型夹杂平均含量为245.8mg/10kg,稳态浇注下为85.75mg/10kg,换包过程中铸坯中大型夹杂物的平均含量为120.25mg/10kg,在非稳态浇注下,铸坯中非金属夹杂物含量较高。铸坯中大部分夹杂物来源并不单一,由脱氧产物与中间包覆盖剂、中间包打结料及结晶器保护渣集聚络合形成。

Study of Micro-inclusion of SPHC Blanks

The type, number, size and distribution of macro inclusion in CC were researched, as the origin of inclusions in blanks were analyzed SPHC blanks about the process of BOF-LF- through method of tracer,Result of the re-search shows ： Macro inclusions in blanks almost have three kinds ： The compound inclusion of Al2 03-CaO-MgO-MnS, about 56% ,inclusion of CaO-Al2O3, about 26.8%, inclusion of MgO-CaS, about 17.2%. The quality content of macro inclusion is 245.8mg/10kg in first billet,under the condition of the steady state cast,the quality content of macro inclusion is 85.75mg/10kg. Under the condition of non-steady state cast, the average content of macro-inclusion is 120. 25mg/10kg,the content of non-mental admixture in beam blanks is higher. Most of macro inclusions are not single sources in slab, the macro inclusions in slab of two or more elements were gathered collision in the molten steel by slag of ladle, covering agent of tundish, knot of tundish and protective slag of mould.