轴承钢GCr15铸坯夹杂物的分析研究

Analysis and Research of the Inclusions of GCr15 Billets

针对国内某厂采用100 t电炉冶炼高碳铬轴承钢(GCr15),在生产过程中很难将铸坯全氧稳定控制在10×10-6以下的情况,采用全尺寸三维分析法和大样电解法对轴承钢铸坯中的夹杂物进行了分析研究。研究结果表明:轴承钢中大型夹杂物含量较高,主要是球型的Al2O3系夹杂和含K的块状夹杂,球型Al2O3类夹杂物主要来源于脱氧产物,含K的块状夹杂主要来源于结晶器保护渣的卷入。通过优化反应器流场和底吹氩气,可以促进大型Al2O3类夹杂物上浮和去除;对于含K的块状夹杂,通过优化结晶器流场和电磁搅拌来减少其卷入。显微夹杂物中Al2O3系夹杂物尺寸较大,钢液中存在少量的Mg或Ca都可以将Al2O3转变为尺寸较小的MgO·Al2O3、MgO或CaO·Al2O3·MgO系夹杂物。

Based on this fact that it is difficult to control of the total oxygen less than 10×10^-6 when smelting bearing steel in a 100 t EAF,the inclusions in bearing steel billets were analyzed by full-size three-dimensional analysis and large sample electrolysis in the paper. The result showed that the content of large inclusions is higher,dominant sphericalAl2O3 system inclusions and the massive inclusions containing K. The spherical Al2O3 system inclusions are mainly derived from deoxidation products and the massive inclusions containing K are mainly come from slag entrapment from the mold. Therefore,the removal effect of Al2O3 system inclusions can be improved by optimization of reactor flow and the effect of ladle argon,and the inclusions containing K are reduced by the optimization of mould flow field and the adjustment of electromagnetic stirring. The Al2O3 group inclusions are larger. A small amount of Mg or Ca exist in the liquid steel can tranfer,Al2O3 group inclusions into the smaller MgO·Al2O3、MgO or CaO·Al2O3·MgO inclusions.