钙处理对高碳铝镇静钢中夹杂物的影响

Effect of calciumtreatment on non-metallic inclusions in high carbon aluminum killed steel

为了研究高碳含硫铝镇静钢中夹杂物的控制策略,利用ASPEX自动扫描电镜研究了钙处理对高碳铝镇静钢中夹杂物形貌、成分等特征的影响。结果表明,钙处理后夹杂物并未由LF精炼结束时的MgO·Al_2O_3转变为低熔点钙铝酸盐,而是转变为x(MgO·Al_2O_3)·(1-x)CaS复杂成分体系,夹杂物中MgO/Al_2O_3的质量比维持在1∶3不变。原因在于,钢液中w([S])/w(T[O])比较高,导致钙主要与硫结合生成CaS,而较少参与MgO·Al_2O_3的改性;精炼渣碱度低使得钙无法还原MgO。在此基础上对钙处理时夹杂物的生成与转变机理进行了讨论。

Influence of calciumtreatment on the composition and morphology of non-metallic inclusions in high carbon aluminum killed steel was studied by automatic SEM（ASPEX）.The results indicated that inclusions transformed from MgO·Al2O3 spinel at LF ending to complicated x（MgO·Al2O3）·（1-x）Ca S inclusions after calciumtreatment,instead of low-melting calcium-aluminates.The mass ratio of MgO/Al2O3 in inclusions which was nearly 1∶3 maintained almost constant during calciumtreatment.Because of w（[S]）/w（T[O]） in steel being so high,calcium combined with sulfur to generate Ca S and didn＇t modify MgO·Al2O3inclusions.On the other hand,due to the basicity of refining slag being so low,calcium in steel cannot reduce MgO of MgO·Al2O3inclusions.On this basis,the generation and evolution mechanisms of inclusions during calciumtreatment were discussed.