The service life of roller bearings strongly depends on nonmetallic inclusions (NMIs). Therefore, these steels request highest metallurgical standards in their production. To determine the effect of the Al₂O₃ content and a protective atmosphere (N₂) on the electroslag remelting (ESR) behavior, laboratory scale experiments are conducted. Changes in the composition of the remelted materials and in the slag are determined. In addition, the amount and composition of the NMI prior and after remelting are investigated, and thermodynamic simulations on the formation of NMI are conducted. Changes in the chemical composition can largely be explained by well‐known equilibrium reactions between the slag and the metal. Lowest Al contents in the remelted steel can only be achieved with the Al₂O₃‐free slag. Higher Al₂O₃ contents in the slag lead to higher oxygen and sulfur contents in the steel and corresponding higher amounts of NMI after remelting. The use of a protective gas mainly reduced the loss of Si and led to lower O and S contents after remelting with the Al₂O₃‐free slag. The composition of the NMI changed from alumina type to MgO–Al₂O₃ (MA)‐spinel type and finally mixed MgO–SiO₂ oxides with decreasing Al₂O₃ contents. These results are confirmed by thermodynamic calculations.

中文翻译：

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炉渣中Al2O3含量对轴承钢重熔行为的影响

滚动轴承的使用寿命在很大程度上取决于非金属夹杂物（NMI）。因此，这些钢在其生产中要求最高的冶金标准。确定Al ₂ O ₃含量和保护气氛（N ₂）关于电渣重熔（ESR）行为，进行了实验室规模的实验。确定重熔材料的组成和炉渣的变化。另外，研究了重熔前后NMI的含量和组成，并对NMI的形成进行了热力学模拟。化学成分的变化很大程度上可以通过炉渣与金属之间的众所周知的平衡反应来解释。重熔钢中最低的Al含量只能使用不含Al ₂ O _3的炉渣实现。较高的Al ₂ O ₃炉渣中的硫含量会导致钢中较高的氧和硫含量，并导致重熔后相应地产生较高的NMI。使用保护气体主要是在与不含Al ₂ O _3的炉渣重熔后，减少了Si的损失，并降低了O和S的含量。NMI的组成从氧化铝型变为MgO-Al ₂ O ₃（MA）-尖晶石型，最后混合了Alg ₂ O ₃含量降低的MgO-SiO ₂氧化物。这些结果通过热力学计算得到证实。