超高牌号无取向硅钢降钛工艺研究及改进

通过分析研究超高牌号无取向电工钢35W230冶炼过程中Ti]的来源和变化趋势,确定了冶炼过程中Ti]含量升高的主要因素,即渣中(TiO₂)还原成为Ti]进入钢水,和硅铁合金中杂质Ti元素进入钢水。同时确定了影响渣中(TiO₂)含量的主要因素,即铁水Ti]含量和转炉铁矾土加入量。通过选择Ti]质量分数约为0.02%的低钛铁水,并降低转炉铁矾土加入量至300 kg/炉,与铁水Ti]质量分数约为0.04%、铁矾土用量约600 kg/炉相比,成品Ti]质量分数从0.004 43%降低到0.002 58%。在此基础上,进一步优化了RH铝脱氧工艺,钢水脱碳时,加铝预脱氧至0.02%~0.03%,加入硅铁进行脱氧和合金化,利用钢水中的氧去除硅铁合金带中的Ti],再加入铝丸和电解锰,最终使钢水中的Ti]质量分数达到了0.002 10%。铸坯全氧质量分数试验炉次为0.001 1%,与正常炉次0.001 0%相差不大。性能上铁损P15/50降低了约0.07 W/kg,磁感J5000提高了0.004 T。

Research and improvement of technology to reduce Ti content in super-high grade non-oriented electrical steel

By researching the source and changing rule of the solution Ti] in super-high grade non-oriented electrical steel 35W230 during the smelting process, the key factors for the increase of solution Ti] in steel were found, that the Ti] came from the reduction of (TiO₂) in the slag and Ti element in ferrosilicon alloy will get into the steel. At the same time, the key influences of the content of (TiO₂) in the slag were also found, which were the Ti] in molten iron and the amount of bauxite added to the converter. By using lower Ti] molten iron with the w(Ti]) was 0.02% and reducing the adding amount of bauxite to 300 kg, compared with the situation of using the molten iron with the w(Ti]) was 0.04% and adding bauxite by an amount of 600 kg, the w(Ti])of the final product was reduced from 0.004 43% to 0.002 58%. Continuously, the deoxidizing measure in RH was further improved. First, when decarburization, Al was added to reduce w(O])to about 0.02%-0.03%. Then ferrosilicon alloy was added intend of deoxidizing and alloying. In this step, the Ti] brought into the steel by ferrosilicon was reduced by the O] in the steel. At last, Al balls and electrolytic manganese were added to the steel. Finally, the w(Ti])in the steel was reduced to 0.002 10%. The total oxygen mass fraction of slab in the experiment was 0.001 1%, which was similar to that of the normal production of 0.001 0%. By reducing the Ti] of the steel, the iron loss P15/50 of the final product was reduced by about 0.07 W/kg. The magnetic induction J5000 was improved by about 0.004 T.