Effects of Al-Mg alloy treatment on behavior and size of inclusions in SUH 409L stainless steel

Abstract

Different types of steel were produced by different deoxidization processes to investigate effects of Al-Mg alloy treatment on the behavior and size of inclusions in stainless steels. Both industrial experiments and thermodynamic calculations were studied. Results showed that irregular and clustered Al2O3 inclusions are dominant in aluminum killed stainless steels. Using Al-Mg alloy treatment, size of Al2O3 inclusions could be reduced, irregular and clustered Al2O3 inclusions can be changed into the spherical MgO ⋅ Al2O3 inclusions. Changes in size and number of inclusions result from that Al-Mg alloy treatment could significantly affect the nucleation process of MgO ⋅ Al2O3 inclusions in molten steel. When the content of Mg is enough, larger inclusions can be reduced by the Al-Mg alloy treatment, and inclusions can keep fine.