钙合金处理硅钢中的夹杂物及晶粒成长变化

采用RH精炼添加钙合金方式对硅钢进行钙处理，结果表明，钙合金添加量为0．67、1．00和1．67kg／t钢时，钢中Ca含量分别为0、2×10^6和4×10^6（质量分数）；随着钙合金添加量的增加，钢中夹杂物粒度逐渐由0～2μm向2～4μm、4～6μm偏移；不同钙处理条件下，钢中均存在粒径小于1μm和粒径为1-5μm的MnS、CuxS夹杂物，后者或单独存在，或与AIN、CaS夹杂复合；钢中粒径为5～10μm的夹杂物基本以Ca的氧化物和硫化物为主。与未经钙处理的炉次相比，钙合金添加量为0．67、1．00和1．67kg／t钢时，粒径小于1．0μm的夹杂物减少幅度分别为68．06％、87．50％和94．94％。钙合金添加量为1．67kg／t钢时，可以去除钢中绝大部分的微细夹杂物。

Change of Inclusions and Grain. Growth of Silicon Steels by Adding Ca Alloy During RH Refining Process

In order to improve the properties of final silicon steels, the calcium treatment was adopted by adding Ca alloys into the liquid steel during the RH refining process. Results show that when the addition of Ca alloys is 0.67 kg/t, 1.00 kg/t and 1.67 kg/t, the corresponding Ca content in silicon steels is 0, 2×10^6 and ×10^6 respectively. With the increase of Ca alloy addition, the particle sizes of inclusions in steels become 2 - 4 μm and 4- 6μtm, from 0-2 μm. Under different calcium treatments, there exist both the MnS and CuxS inclusions whose sizes are below 1 μm and the MnS and CuxS inclusions whose sizes are 1-5 μm. The latter are composed with the AIN and CaS inclusions or exist alone, and the inclusions with a size of 5 ~ 10 pm in steels are mainly oxide and sulfide of calcium. Meanwhile, compared with the untreated steels, when the addition of Ca alloys is 0.67 kg/t, 1.00 kg/t and 1.67 kg/t, the numbers of inclusions whose sizes are below l.O gm will decrease by 68.06%, 87.50% and 94.94% respectively. When the addition of Ca alloy reaches to 1.67 kg/t, most of the superfine inclusions in final silicon steels can be removed.