Fundamental Study On Microstructure Of Molten Flux For Non-reactive Continuous Casting

By systematically studying the slag micro structure of non-reactive continuous casting flux and analyzing the relationship between micro structure and rheological behavior,the theoretical basis is provided for the development of non-reactive continuous casting flux and the development of continuous casting technology of high aluminum and high manganese steel is promoted.The chemical composition of non-reactive continuous casting mold flux was designed through molecular dynamics simulation and thermodynamic calculation.The results show that the depolymerization degree of each component to the slag network structure follows the following:Na2O>Li2O>MgO>BaO>CaF2.The chemical composition range of non-reactive continuous casting mold flux is:(Al2O3)/(CaO)is 1,(B2O3)is 5%,(Na2O)is 8%?11%,(Li2O)is 1%?4%,(MgO)is 4%?7%,(BaO)is 6%?9%d(CaF2)is 5%-8%Raman spectroscopy and nuclear magnetic resonance spectroscopy were used to study the non-reactive mold flux for continuous casting.The results show that:The primary and secondary order of influence of mold flux cosolvent on polymerization degree of slag network is as follows:Na2O>Li2O>MgO>BaO>CaF2,some F ions in the non-reactive mold flux slag will replace O to form a relatively stable[AlO3F]tetrahedron structure,and connect with[AlO4]5-tetrahedron to form a three-dimensional network structure.The primary and secondary order of cosolvent in the slag to the tetrahedron structure in the slag network structure is Na2O>MgO>BaO>Li2O>CaF2.The rheological behavior of mold flux was studied by rotating cylinder method.The results show that there is a good linear relationship between rheological behavior and microstructure.The lower the polymerization degree and viscosity of slag,the more stable the slag structure,the more difficult the crystal to precipitate,and the lower the turning temperature.Figure38;Table 19;Reference73.