静磁场对吹氩结晶器内弯月面行为的影响

用Pb-Sn-Bi液态合金模拟了吹氩和施加静磁场时结晶器内弯月面处的流动现象,观察磁场对吹氩引起的弯月面失稳的抑制作用.结果表明,施加磁场改变了Ar气泡通过弯月面的漂浮分布规律,加强了气泡在水口和窄面之间的漂浮,使Ar气泡在结晶器宽度方向上漂浮分布更均匀,减小了水口附近由于大量气泡上浮对液面的扰动.施加0.5 T磁场能对水口出流以及吹氩所产生的液面波动产生抑制作用.由相似准则推得,应用在实际连铸机上抑制吹氩板坯连铸结晶器内液面波动的合适磁场强度为0.36 T.

DEVELOPMENT OF A NEW HIGH STRENGTH AND GOOD HOT CORROSION RESISTANCE FOR LOW SEGREGATION SUPERALLOY DZ68

The liquid alloy of Pb-Sn-Bi was used to simulate the fluid flow phenomena in the continuous casting mold under argon gas injection and with electromagnetic field. The depressed effect of magnetic field on the fluctuation of meniscus was observed. The results show that when the magnetic field is imposed, the distribution of argon gas bubbles floating is changed, and the floating up of gas bubbles between the nozzle and the narrow side of mold is strengthened, hence the distribution of gas bubbles in the width direction of mold is more uniform, and the disturbance of floating gas bubbles near the nozzle on the meniscus is decreased. The magnetic field of 0.5 T can depress the fluctuation of meniscus caused by both injected argon gas and discharged stream from the nozzle. According to the similarity rule, it is deduced that the suitable magnetic flux density for depressing the fluctuation of meniscus in the slab continuous casting mold with argon gas injection is 0.36 T for the practical continuous caster.