| 摘要 |
PURPOSE:To reduce content of Al2O3 inclusion in molten steel and to produce stainless steel having high purity by executing VOID treatment to Cr-containing molten steel, raw material of stainless steel of which pre-decarbonizing and refining have been executed in a converter, and after that, stirring molten slag and the molten steel. CONSTITUTION:After pre-decarbonizing and refining high-carbon Cr-containing molten iron by blowing oxygen in the converter, the molten steel is decarbonized to the aimed C content by vacuum decarbonization using a VOD apparatus. Successively, after completing degassing treatment by blowing Ar gas, deoxidizers of Al, Fe-Si, etc., are added and further, by adding CaO-based flux, the molten slag having <=10% SiO2 is made. Next, the molten steel is stirred by blowing Ar gas, and Cr2O3, FeO, MnO, etc., in the molten slag are reduced and recovered by residual Al in the molten steel and the total content of these compounds in the molten slag is made <=3%. The Al2O3 generating by this reaction is absorbed into the CaO-based molten slag and pure stainless steel having extremely little Al2O3 content as on-metallic inclusion in the molten steel is produced.
|
