WAVE SUPPRESSION OF MOLTEN-METAL BY IMPOS ING BOTH STATIONARY MAGNETIC-FIELD AND DIRECT ELECTRIC-CURRENT

Suppression of wave motion of molten metal surface is one of the most important technology for controlling initial solidification in various casting process, e.g. continuous casting, twin roll casting, etc, whe re the suppression of wave motion can improve surface quality of cast metal. The wave motion is motivated by gravity force, so that the dimi nution of apparent gravity force by imposing vertical electromagnetic force must be successful for wave suppression. In this paper, at first , based on this principle, frequency changes of wave motion were measu red in two imposition types of both stationally magnetic field and dir ect electric current. In case current was parallel to the wave vector, the frequency did not change. On the other hand, in case magnetic fie ld was parallel to the wave vector, the frequency did change according to the dispersion relation modified by apparent gravity force. Next, from the standpoint of the process control in actual applications, ano ther experiment was conducted where the imposition area of electric cu rrent is limited to around meniscus. As the results, it was found that this technique for wave suppression is still effective for deep molte n metal pool.