无取向电工钢WG350生产过程中夹杂物的行为与控制

摘要：为了更好地控制WG350无取向电工钢中的夹杂物，采用扫描电子显微镜、Aspex系统分析了精炼、连铸过程和成品板中夹杂物的类型、数量及尺寸的演变规律。结果表明，氩站开始出现大尺寸含P复合夹杂物，该类型夹杂物大部分在RH脱碳后会上浮去除。RH加铝脱氧时生成的Al2O3以团簇状和块状为主，前者尺寸范围为0.5~5μm且大部分被去除，而块状Al2O3会一直遗留至成品中。RH合金化后，钢液中夹杂物数量达到最大，夹杂物类型除Al2O3外，主要还有复合氧化物、复合氧硫化物。成品板中夹杂物种类及数量关系为：氧硫化物＞氧化物＞氮化物＞氮化物+氧化物＞氮化物+硫化物＞氮 氧 硫复合物＞硫化物。钢中氧硫(质量分数)由49×10-6降低至13×10-6时，夹杂物种类及数量均会大幅度减少。

Evolution and control of inclusions in non oriented electrical steel WG350 during production process

In order to control the inclusions in WG350 non-oriented electrical steel, the evolution of the type, quantity and size of inclusions in refining, continuous casting and finished plate samples were systematically analyzed by scanning electron microscope (SEM) and Aspex. The results showed that large size P containing composite inclusions appear in the CAS station, and most of these inclusions would float up and be removed after RH decarbonization. The Al2O3 produced after RH deoxidation were mainly clustered and massive. The spherical Al2O3 had a size range of 0.5-5μm and most of them were removed, while the massive Al2O3 would remain in the finished product. After RH alloying, the number of inclusions in the molten steel reached the maximum. In addition to Al2O3, the types of inclusions mainly included composite oxides and composite oxysulfides. The types of inclusions in the finished plate were: oxysulfide, oxide, nitride, nitride + oxide, nitride + sulfide, nitride + oxysulfide, sulfide, and their number decreased in order. When the total amount of oxygen and sulfur in steel was reduced from 49×10-6 to 13×10-6, the type and quantity of inclusions will be greatly reduced.