PURPOSE: To cosiderably decrease the rate of generation of longitudinal cracks in an ingot by providing gas-liquid cooling mechanisms to part or the whole of a continuous casting machine up to just before its final ingot leveling point.
CONSTITUTION: Upper and lower rolls 20 for known ingot guides are provided below a mold 21 and an ingot S is fed to a conveying table 22 via a final leveler 19. In this case, plural pieces of gas-water spray nozzles 11 are disposed in the spacing directions of the respective upper and lower rolls 20 in a predetermined ingot cooling adaptive zone C. The zone C is beforehand segmented to plural cooling zones C1W C4, and the respective supply systems for gas and liquid for each thereof are branched from the main pipes 1, 21 provided above the upper rolls and below the lower rolls. Next, the cooling patterns and cooling speeds of the zones C1WC4 determined by the kind of steel of the ingot S are beforehand inputted to a setter 30, and the flow speed of the air discharged from a pressure air supply end pipe to a mixing pipe 10 is operated at an arithmetic device 31. Also, the flow rates of cooling water from the respective cooling water control main pipes 2 are operated. Next, the operated values are introduced to the cooling water controller 32 of the control main pipes 2, 12 and a pressure air controller 33, and the gas-water mixed mists of desired flow speed are sprayed 11 to the ingot S.
TSUNEOKA SATOSHI
WAKE MAKOTO
TAKAHAMA HIDEYUKI
ASOU TOSHIROU
