RH精炼喂CaSi线去除无取向硅钢中的非金属夹杂物

Removal of Non-metallic Inclusions in Non-oriented Silicon Steel by CaSi Wire Feeding During the RH Refining

结合工业化生产的无取向硅钢,进行了RH精炼喂CaSi线去除钢中的非金属夹杂物试验研究。针对不同的钙处理条件,分析了CaS夹杂生成热力学,观察了夹杂物的形貌和尺寸分布,确定了夹杂物的类型、数量,探讨了钙处理后钢中夹杂物的变化规律。结果表明,本试验条件下,钙处理可以有效抑制MnS、AlN夹杂物的生成,有效促进钢中微细夹杂物的聚合、上浮、去除,钢质纯净度明显提高。经过合适的钙处理后,钢中的夹杂物以独立存在的CaO为主,同时有少量含CaO、SiO2、MgO的复合夹杂,没有发现CaS夹杂存在。这部分夹杂物的尺寸集中分布在2～20μm,数量约为1.8×105个/mm3。

Experimental study on removal of non-metallic inclusions in non-oriented silicon steel obtained from industrial production by CaSi wire feeding during RH refining process was carried out. The thermo- dynamics of CaS inclusion formation was analyzed , the morphology and the size distribution of inclusions were observed, and the numbers and types of inclusions were also determined for the steel specimens treated under different calcium treatment conditions. Furthermore, the variation of inclusion characteris- tics after calcium treatment was discussed. The results show that due to calcium treatment, the formation of MnS and A1N inclusions can be restrained, and the aggregation, flotation and removal of micro-inclu- sions can be efficiently boosted. As a result, the cleanliness of liquid steel is noticeably improved. The main types of inclusions are single phase of CaO, and some complex inclusions are composed of CaO,SiO2 and MgO, and no CaS inclusion is found after an appropriate calcium treatment. The size of all the inclusions is in the range of 2 μm to 20 μm, and their amount is about 1.8 × 105/mm3.