METHOD FOR UNIFORMLY FORMING SOLIDIFIED SHELL IN TWIN ROLL CONTINUOUS STRIP CASTING PROCESS AND MENISCUS SHIELD USED THEREIN

摘要

PURPOSE: A method is provided which uniformly forms a thickness of solidified shell by differing environmental gas of the center part of casting rolls from that of the edge part of the rolls, thereby decreasing the difference of solidification capabilities of the center and edge parts of the casting rolls, and a meniscus shield is provided which can be applied to the same casting method and uses different types of gases. CONSTITUTION: In a method for manufacturing a strip in a strip casting machine in which molten steel is supplied through a nozzle between a pair of casting rolls, the method for uniformly forming solidified shell in the twin roll continuous strip casting process comprises the processes of maintaining an argon gas environment at the center part of the casting rolls; and gradually increasing a ratio of nitrogen in a mixed gas of argon and nitrogen at the edge part of the casting rolls so that nitrogen gas environment is maintained when expansion of the casting rolls reaches to the normal state. In a strip casting machine comprising a meniscus shield on the bottom surface of which weirs (12) are installed for preventing oxides formed on the surface of molten steel pool from being mixed into the casting rolls by forming a molten steel pool between a pair of casting rolls, the meniscus shield (10,20) comprises in which different environmental gases can be used is characterized in that partition means (22a,22b) are additionally installed at the meniscus shield so that environmental gases of the casting rolls and both edge parts are maintained differently by continuously contacting with outer side wall of the weir and the bottom surface of the meniscus shield.