Model of “Liquid Window” by Calcium Treatment in Medium Carbon Steel
MA Zhi-fei1，SUN Yan-hui1，ZENG Ya-nan1，AI Xi1，LIU Rui-ning2，LIU Yong2
1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing，Beijing 100083， China 2. Shijiazhuang Iron and Steel Group Corporation，Shijiazhuang 050000， Hebei， China
Abstract：The variations of inclusion types in Q345B steel was investigated before and after calcium treatment. The modification mechanism of alumina and the condition of the precipitation of calcium sulfide were analyzed by thermodynamics. Meanwhile, the model of “liquid window” regarding the modification of inclusions was established. Thermodynamic calculations show that : in order to modify the alumina inclusions to liquid calcium aluminate, the content of calcium in steel from 0.0017% to 0.0102% is needed when the aluminum in steel is 0.016% at 1873K. The result of industrial production reveals that alumina can be modified into 12CaO·7Al2O3 or CaO·Al2O3 inclusion when the content of calcium in steel is between 0.0014%and 0.0017%. While MnS just can be partially modified into CaS and no single precipitation of CaS occurred.
马志飞，孙彦辉，曾亚南，艾西，刘瑞宁，刘泳. 中碳钢钙处理夹杂物变性的“液相窗口”控制模型[J]. 钢铁, 2013, 48(11): 37-42.
MA Zhi-fei，SUN Yan-hui，ZENG Ya-nan，AI Xi，LIU Rui-ning，LIU Yong. Model of “Liquid Window” by Calcium Treatment in Medium Carbon Steel. Iron and Steel, 2013, 48(11): 37-42.
2013, Vol. 48 
