低频电磁铸造过程中温度场的形成机理

通过理论解析研究了电磁场引起铸造过程中温度场改变的原因,并通过在铸造过程中连续测温的方法进行了实验验证.结果表明,低频电磁铸造对温度场产生影响的主要原因是低频电磁场引起熔体强制对流.强制对流对熔体产生强烈的搅拌作用,促进了熔体内部的热交换,加强了熔体与结晶器壁(石墨环)以及熔体和固液界面的传热,使熔体温度场非常均匀,接近于同一温度.研究还发现,低频电磁铸造过程对浇注温度不敏感,改变浇注温度,结晶器内熔体温度变化不大.

Mechanism of Forming Temperature Field During Low Frequency Electromagnetic Casting

How the temperature filed changes with the electromagnetic field was theoretically analyzed for low frequency electromagnetic casting(LFEC) and the results were experimentally verified by continuous temperature measuring in the casting process.It is shown that the forced convection of melt resulting from low frequency electromagnetic field functions as stirring the melt,thereby promotes the inside heat exchange of the melt and enhances the heat transfer between melt and mould and between melt and solid/liquid interface.A very uniform temperature field of melt was thus formed with almost the same temperature.It is also found that adjusting casting temperature can not change the melt temperature too much,indicating the low sensitivity of LFEC to the casting temperature.