Regular Article

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

¹ State Key Laboratory of Advanced Steel Processing and Products, Central Iron and Steel Research Institute, Beijing, PR China
² National Engineering and Research Center for Continuous Casting Technology, Central Iron and Steel Research Institute, Beijing, PR China

^* e-mail: mengying512712_2005@126.com

Received: 10 October 2016
Accepted: 29 September 2017

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.