HEATING METHOD FOR STEEL BILLET FOR HOT ROLLING

摘要

PURPOSE:To simply and easily dissolve bad influence of a skid mark upon a rolled product, by preliminarily, locally heating a scheduled skid mark position of a billet before charging it into a heating furnace, and then, by charging the billet into the heating furnace for heating it to prescribed temperatures. CONSTITUTION:An electrical induction heating is preliminarily, locally applied to a sheduled skid mark position 10 of a billet 9 placed upon an entry table just before charging it into a heating furnace, for heating the position 10 to about 700 deg.C. The electrical induction heater is constituted by winding an electromagnetic coil 8 around an iron core 7; the size and shape of the iron core 7 and electromagnetic coil 8 are determined so as to give a local induction heating to a scheduled skid mark position 10 of a billet 9 to be fed to a hot rolling pass. An electrical current is supplied to the electromagnetic coil 8 which then locally heats the billet 9 mainly depending on an eddy current loss. Then, the billet 9 is charged into the heating furnace for heating it to prescribed temperatures.