PURPOSE: To decrease the hollow defects on slab surfaces and make stable conditioning-free rolling possible by subjecting the surfaces of the continuously cast slab right after the passage through molds to spray coolig controlled to a prescribed water flow range and trimming the shape of the slab.
CONSTITUTION: While slab broad sides 1, 1' are being put in abutment on broad surface water cooling steel plates 2, 2' and slab narrow surface sides 3, 3' on narrow surface water cooling plates 4, 4' respectively, the slab is continuously cooled and drawn downward, whereby a continuously cast slab is produced. Next, the slab past the water cooling molds 2, 2', 4, 4' is supported at its broad surface sides by flat rolls 5, 5' and its narrow surface sides by side rolls 6, 6' respectively. In this case, spray nozzles for cooling water are disposed on the slab surfaces (broad and narrow surfaces) right after the passage through the molds 2, 2', 4, 4' and the flow rates of the water thereof are controlled in a 3W10cc/cm2.sec range. The shape of the slab is trimmed by the spray cooling with this cooling water. As the spray nozzles, the nozzles shown by 7, 7', 8, 8' and 9, 9' respectively are disposed respectively in the uppermost stage, the 2nd stage and the 3rd stage.
KAWAI YUTAKA
MURANAKA YUTAKA
YASUZAWA KEIJI
KAMIMURA ICHIROU
