Research In Properties And Microstructure Of Mold Flux Under High Frequency Magnetic Field

Along with the progress of the electromagnetic metallurgy technology,the electromagnetic field is increasingly widely used in the iron and steel metallurgy industry.For example,the quality of billet was improved and slab surface defects and internal defects were reduced because of the application of electromagnetic continuous casting technology.Meanwhile,as the metallurgical auxiliary materials,mould flux was of great importance for the technology of anterograde and slab quality in the process of continuous casting process.Under the environment of electromagnetic field,rheological properties in high temperature of mould flux which was silicate structure will be changed because of electromagnetic force.High temperature rheological properties will be changed,so as to influence the membrane properties and microstructure of mold flux slag.There is little research about the characteristics of the mold flux under electromagnetic,In order to study the mold flux's characteristics under electromagnetic.mold flux in Industrial production was used to measure metallurgical behaviours such as high temperature rheology,solidification crystallization etc.Samples were made under different temperature,cooling intensity,composition to study the influences of high frequency electromagnetic field,during this procedure X-ray powder diffraction,mineralographic microscope,infrared monitor,Raman spectrometer,conclusion were drawn:1)The Si-O tetrahedral network structure is destroyed and produces a simple structure of low melting compound anions conditions when increasing the alkalinity or alkaline oxide content without magnetic field.Not only the degree of polymerization of the anionic group is reduced,and the viscosity of the mold powder and the activation energy of the viscous flow are also reduced.The flowability of the mold powder is improved due to the increase in the flowability thereof,so that the thickness of the slag film is more lower.On the contrary,silica ion groups are more easily polymerized together to form larger ions due to electromagnetic forces When there is a high frequency electromagnetic field.These large ion groups increase the viscosity of the flux and the activation energy of the viscous flow,resulting in reduced rheological properties.Moreover,the longer the electromagnetic force acting time,the more obvious,the fluidity of the slag film increases,and the crystallization rate increases.2)With the increase of temperature,the viscosity of the slag decreased,the activation energy decreased,and the thickness of the slag film and the crystallization rate decreased.3)In the magnetic field,the Gibbs free energy of the nucleation of the flux is reduced,and the nucleation rate of the crystallization rate of the flux were increased.4)The microstructures of the mold flux are changed,and the dimer Q₁decreased and the chain structure Q₂increased,which increased the network degree and viscosity.Figure 50;Table 18;Reference 72...