Composition Change of the Non-metallic Inclusions during the Secondary Refining of Low Oxygen Alloyed Structural Steels
High basicity and high Al2O3 slag was used in secondary refining of alloyed structural steels aiming at decreasing total oxygen content (TO) of steel and forming relatively lower melting temperature inclusions to improve the fatigue properties of the steels. It was found that TO at the end of LF and RH refining both decreased with increasing slag basicity. When Al2O3 in the slag was less than 25 mass％, TO increased with increasing slag Al2O3 content. While, when AI203 in the slag was higher than 25 mass％, TO decreased with increasing slag Al2O3 content. In the refining, composition of the non-metallic inclusions changed in order of inclusions of Al2O3→ inclusions of MgO-AI203 system→ inclusions of CaO-MgO-Al2O3 system, among which, the transfer of inclusions of MgO-Al2O3 system to inclusions of CaO-MgO-Al2O3 system was inwardly from outside surface and the reaction speed was relatively slower. Hence, at the end of the LF refining, there were still many unchanged MgO-Al2O3 system inclusions. The TO content of the steel largely affects the transfer of the inclusions and decreasing TO content could increase the transfer degree of the inclusions.`
Alloyed structural steel Secondary refining Slag Non-metallic inclusions Melting temperature
Xinhua WANG Kewen ZHAO Haibo LI Ying WANG Tianming CHEN
School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing R&D Center,Panzhihua Iron and Steel Corporation
国际会议
2008 International Symposium on Clean Steel(2008年洁净钢生产技术学术研讨会)
鞍山
英文
40-46
2008-09-17（万方平台首次上网日期，不代表论文的发表时间）