The theoretical and numerical calculation and experimental study on soft contact electromagnetic casting forming
Based on classical electromagnetic theory, the electromagnetic pressure calculation model and the formula of electromagnetic casting forming have been established. Theoretical and numerical results indicated that the frequency, current density, relative permeability of alloy melt and resistivity can also influence the effect of electromagnetic pressure. Meanwhile, the effect of metal physics properties parameters on the value of electromagnetic pressure is more complicated. The needed magnetic field for casting Al-Si alloys liquid column with length of 0.05m in experiment was very close to the theoretical value. This result indicated that the formula of electromagnetic casting forming can be used to guide experiments and the actual industrial production.
Numerical Simulation of Heat Transfer and Deformation of Initial Shell in Soft Contact Continuous Casting Mold Under High Frequency Electromagnetic Field
Heat transfer and deformation of initial solidification shell in soft contact continuous casting mold under high frequency electromagnetic field were analyzed using numerical simulation method; the relative electromagnetic parameters were obtained from the previous studies. Owing to the induction heating of a high frequency electromagnetic field (20 kHz), the thickness of initial solidification shell decreases, and the temperature of strand surface and slit copper mold increases when compared with the case without the electromagnetic filed. The viscosity of flux decreases because of the induction heating of the high frequency electromagnetic field, and the dimension of the flux channel increases with electromagnetic pressure; thus, the deformation behavior of initial solidification shell was different before and after the action of high frequency electromagnetic field. Furthermore, the abatement mechanism of oscillation marks under high frequency electromagnetic field was explained.
Electromagnetic control of initial solidification in continuous casting of steel by low frequency alternating magnetic field
A marked improvement of the surface quality of casts and a break-through in casting speed in conventional continuous casting of steel require the introduction of new technology for initial solidification control. The authors have approached these problems by the use of electromagnetic shaping of the meniscus and demonstrated the possibility using simulation experiments. This paper describes the results of numerical prediction of the effect of electromagnetic field on the initial solidification of steel and the experimental results obtained by continuous casting of round austenite stainless steel billets of 180 mm diameter with solenoidal magnetic field with main frequency, 60 Hz. The numerical results concerned with magneto-hydrodynamics and heat transfer phenomena predicted improvement of the surface roughness of the cast billet and improvement of mold lubrication by decreasing the dynamic pressure due to the meniscus shaping effect. In the experimental casting, the surface of billets were smoothed and the mold friction force was reduced by imposing the magnetic field, which are in consistent with the numerical predictions.