Deng Kang

STUDY ON THE FLUID FLOW IN SLAB CONTINUOUS CASTING MOLD WITH ELECTROMAGNETIC BRAKE

The flow patterns were simulated by Hg in high speed continuous casting mold with electromagnetic brake.The velocity in mold and fluctuation of meniscus was measured by ultrasonic doppler velocity.The effect of the magnetic field on the fluid flow was analyzed.The influence of magnetic flux density and location on the flow discharged from the nozzle,the velocity in mold,the fluctuation and flow of the meniscus,and the washing intensity of flow were studied.The results showed that the flow discharged from the nozzle was suppressed,the flow in the upper eddy was strengthened, the flow in the lower eddy was weakened,and the fluctuation of free surface and the flow at the meniscus were improved.The magnetic field could not only damp flow,but also change the flow direction and redistribute the flux of liquid steel.When B_(max) was higher than 0.29 T,it was beneficial to optimizing and controling the flow in the mold.

Effect of distribution of magnetic flux density on purifying liquid metal by travelling magnetic field

The distribution of the magnetic flux density in the magnetic field generator which provided travelling magnetic field was determined. The experiments using liquid gallium and aluminum — silicon alloy to observe the turbulent flow or remove inclusions were performed to obtain the basic principles how the distribution of the magnetic flux density took effect on removing inclusions from molten metal by electromagnetic field. The suitable area in the field for purifying metal was suggested.

PHYSICAL SIMULATION OF Ar BUBBLE BEHAVIOR IN THE SOLID/LIQUID INTERFACE OF CONTINUOUS CASTING BILLET

Ar gas was injected to the nozzle during continuous casting to prevent from nozzle clogging caused by solid inclusions,however,some gas bubbles were captured by the initial solidified billet shell,and subsequently billet defects were formed in final product.In present work,a physical model applying mold simulator was designed and used to investigate the bubble behavior in the solid/liquid interface.Different mold simulator angels and bubble diameters were considered,three typical behaviors were observed,some bubbles were captured by the solidified shell,several bubbles coalescence in the solid/liquid interface,and other bubbles stayed in the interface for a moment,and then left.The possible mechanism of gas bubble entrapped in solidified shell was analyzed.Besides, industrial billets were studied,many dendrites were found around the hole,it was considered to be a key factor for gas bubble engulfed in the solidification billets in the meniscus area.Further more,the effective technologies,such as electrical brake near the submerged entry nozzle and electrical stirring in the mold narrow face,can improve billet quality and reduce gas bubbles in solidified shell were imposed.

EXPERIMENTAL STUDY ON FLOWIN SLAB MOLD CONTROLLED BY JET–PATTERN MAGNETIC FIELD

A mercury model was developed to investigate the control of the jet-pattern magnetic field on the flow in medium and heavy slab continuous casting mold.The velocities in mold with and without magnetic field was measured by ultrasonic Doppler velocimeter.The influences of the magnetic field on the flow discharged from the nozzle,the flow in the mold,the flow at the meniscus and washing intensity to wall were analyzed and studied.The results showed that the flow discharged from the nozzle is suppressed,and dissipated before impinging against wall,the flow in the upper eddy is strengthened,the flow in the lower eddy is weakened,and the flow at the meniscus is improved by jet-pattern magnetic field.Compared with electromagnetic braking(EMBr) ruler,the brake effect of the the jet pattern magnetic field on the flow discharged from the nozzle and the flow at the meniscus are the better.

Improvement of the structure and the electromagnetic characteristics of an induction ladle furnace

Based on a numerical analysis of the alternating electromagnetic field in the process of Steel refining with an induction ladle furnace (ILF), the optimization of the structure of ILF and the electromagnetic field for melting is realized in the present work. The optimization of the ILF by outward extension of inner yokes can decrease the magnitic flux leakage obviously, reduce the eddy current energy loss dramatically and then, decrease the total power consumption.