利用低熔点Sn+3.5wt%Pb合金模拟钢的凝固末端电磁搅拌的实验条件,研究了电磁驱动力对铸坯凝固进程的影响。研究表明:在电磁驱动力作用下,半固态区存在一个边界层,边界层表征电磁驱动力作用的极限区域,边界层以内熔体的流速随着搅拌器线圈电流的增大而增大,电磁场对边界层以外的熔体影响不大;电磁搅拌驱动力使固-液界面或边界层向外推移,铸坯凝固坯壳变薄;电磁搅拌力对半固态的金属熔体具有熔蚀、冲刷作用,阻碍柱状晶生长,使凝固壳生长均匀,且内表面光滑无突起。

In this experiment, lower melting point Sn+3.5wt%Pb alloy was served as experiment material, through experiment simulating finite electromagnetic stirring of continuous casting of steel, effect of electromagnetic driver force on the solidifying process of billet was researched. The results show that under electromagnetic driver force, there is a boundary layer in the semi-solid zone, the boundary layer is the maximum zone of electromagnetic force affecting on the metal molten. Velocity of melt within boundary layer is increased with electric current in coil increasing, but no affecting is on the melt beyond boundary layer. Electromagnetic stirring pushes the boundary layer out symmetrically, and makes the solidifying shell thickness thinner. Meanwhile, the growth of dendrite is counteracted; prominences on the interface become smaller and even escape.