精炼渣对高锰钢中非金属夹杂物的影响

 为了研究精炼渣对高锰钢中非金属夹杂物的影响，采用渣/钢平衡的试验方法研究了MgO SiO2 Al2O3 CaO系精炼渣对Fe xMn高锰钢(x=10%, 20%)中非金属夹杂物的影响。结果表明，无顶渣情况下，高锰钢中夹杂物主要为MnO类和MnO Al2O3类2类。加入精炼渣后，夹杂物类型发生了变化，主要有 MnO类、MnO SiO2类和 MnO Al2O3 MgO类3类，其中MnO SiO2类数量最多。采用ASPEX扫描电镜对夹杂物的平均成分进行分析，无顶渣时高锰钢中夹杂物的成分主要是MnO，质量分数在95%以上，并含有质量分数为4%左右的Al2O3。加入精炼渣后，夹杂物中MnO质量分数降低，SiO2质量分数显著增加，MgO质量分数增加。热力学计算结果表明，加入精炼渣后，渣/钢间反应4［Al］+3(SiO2)=2(Al2O3)+3［Si］和2［Mn］+(SiO2)=2(MnO)+［Si］的吉布斯自由能均小于零，这说明在本试验条件下，钢液中的［Al］和［Mn］会还原渣中SiO2，生成的［Si］进入钢液，进而与钢液中的［O］结合，导致夹杂物中SiO2增加。

Effect of refining slag on non metallic inclusions in #br# high manganese steel

In order to research the effect of refining slag on non metallic inclusions in high manganese steel, the effect of the MgO SiO2 Al2O3 CaO refining slag on non metallic inclusions in the Fe xMn high manganese steel (x=10%, 20%) was studied by slag/steel equilibrium experiments. The results show that there are two types of inclusions in the high manganese steel without top slag， MnO and MnO Al2O3. After the addition of the refining slag, the inclusions transformed to three main types, which were MnO, MnO SiO2 and MnO Al2O3 MgO. Among them, the MnO SiO2 type shares the majority of the total inclusions. According to the result analyzed by the ASPEX scanning electron microscopy, the main component of inclusions in the master high manganese steel is MnO, with the mass percent above 95%, and the mass percent of Al2O3 about 4%. After reacting with the refining slag, the mass percent of MnO in the inclusions decreases, while that of SiO2 and MgO increases, especially SiO2 increases significantly. The thermodynamic calculation results show that the Gibbs free energy change of both reactions (4［Al］+3(SiO2)=2(Al2O3)+3［Si］ and 2［Mn］+(SiO2)=2(MnO)+［Si］) between the slag and the molten steel is much less than zero. It indicates that under present experimental conditions, SiO2 in the slag can be reduced by ［Al］ and ［Mn］ in the molten steel to supply ［Si］, which then reacts with ［O］ in the molten steel, leading the SiO2 content in the inclusions.