Effect of electrode change on solidification of slag and metal pool profile in electroslag remelting process

A two-dimensional axisymmetric model is established to study the effect of electrode change on the solidification of slag and metal pool profile during electroslag remelting process. The basic considerations of flow and heat transfer are included in the model, and the growth of ingot is described by the dynamic mesh technique. The electrode melting rate is predicted based on the transient thermal conductivity model between slag and electrode. The results indicate that in the electrode change stage, the slag temperature drops from 1847 to 1763 K gradually and the "hot heart" phenomenon is observed. And the metal pool profile is slightly changed with a depth decrease from 0.3984 to 0.3688 m. In the heating and melting stage of new electrode, the maximum slag temperature firstly increases from 1763 to 1892 K, then decreases to 1845 K, and finally at 3558 s, the maximum slag temperature is stable at 1884 K. Solidified slag shell with a maximum volume of 7.31 x 10(-3) m(3) is formed at the electrode tip, and then, the solidified slag melts completely. The depth of metal pool firstly rises to 0.3700 m and then drops to 0.3565 m. As the preheating temperature of the new electrode increases from 473 to 973 K, the maximum volume of solidified slag decreases from 0.00748 to 0.00592 m(3), and the time from heating to melting of the new electrode decreases from 996 to 887 s.