Abstract：During the refining process of 37Mn5 steel production, the compositions of inclusions changed from Al2O3 to Al2O3-CaO-SiO2-MgO-CaS, without calcium treatment. The inclusion analysis result of samples taking from production showed there was a significant difference between the compositions of larger inclusions and smaller ones. The changing tendencies during refining process varied in inclusions with different size group. The inclusions with diameters larger than 10 μm had similar compositions to the refining slag. Thus these inclusions were caused by slag entrapment. 1.17 wt % calcium was detected in Fe-Si alloy, which resulted in similar effect to calcium treatment, as big amount of small size CaS inclusions were formed in a short time. The analysis of compositions, amounts and morphologies of inclusions, slag compositions and thermodynamic calculation indicated that inclusions evoluted due to deoxidation, refractory corrosion, slag entrapment, reactions between calcium and liquid steel, reactions between inclusions and liquid steel. The mechanism of inclusion evolution during refining process of 37Mn5 steel production was revealed.
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2020, Vol. 55 
