FORMATION OF CAST BILLET IN CONTINUOUS CASTING MACHINE

摘要

PROBLEM TO BE SOLVED: To stabilize the unit wt. of a cast billet by adjusting the shape of the cast billet to a target size in the case of varying kind of steel or casting condition in a billet CC or a middle cross sectional bloom CC. SOLUTION: At the time of forming the cast billet 8 with plural pairs of rolling reduction rolls 10 arranged near the end stage of solification in the continuously cast billet and enabling the positional control in the thickness direction of the cast billet, the rolling reduction rolls 10 are pushed on the surface of a dummy bar 12 at the time of inserting or drawing out the dummy bar 12 having the known thickness D and the position of the rolling reduction roll pairs 10 at this time point, is adjusted to the reference position. After starting the casting, the thickness of the cast billet 8 before executing the rolling reduction at the inlet side of the rolling reduction roll pair 10, is measured and the rolling reduction quantityΔH1-ΔHi for each rolling reduction roll pair 10 is obtd. from the measured cast billet thickness and the finish target cast billet thickness. The position Hs1-Hsi of each rolling reduction roll pair 10 is obtd. from the known thickness D of the dummy bar 12 and the reference position so as to become the obtd. rolling reduction quantityΔH1-ΔHi and set, and the rolling reduction is applied to the cast billet 8 in order.