Continuously casting steel strip

An apparatus for producing thin cast strip by continuous casting comprising:

• a) a pair of casting rolls having a nip therebetween;
• b) a metal delivery system comprising a first core nozzle and a first tundish for delivering molten metal into a casting pool between the casting rolls above the nip, and first side dams adjacent the ends of the nip to confine said casting pool;
• c) a casting roll drive to counter-rotate the casting rolls to form solidified metal shells on casting surfaces of the casting rolls and cast thin steel strip through the nip between the casting rolls from said solidified shells;
• d) two preheating chambers removed from an operating position for casting, each capable of preheating at least a portion of at least one second side dam to a temperature to avoid thermal shock when contacted by molten steel while casting continues;
• e) a gate capable of interrupting the flow of molten metal to the casting pool;
• and capable of resuming flow of molten steel to reform the casting pool;
• f) a first transfer device capable of rapidly removing from an operating position at least portions of at least one of said first side dams desired to be replaced while leaving other components in an operating position;
• and
• g) a second transfer device capable of rapidly transferring at least portions of at least one second side dam for replacement from the preheating chamber to the operating position for casting while leaving other components in an operating position.

An apparatus of producing thin cast strip by continuous casting comprising:

• a) a pair of casting rolls having a nip therebetween;
• b) a metal delivery system comprising a first core nozzle and a first tundish for delivering molten metal into a casting pool between the casting rolls above the nip, and first side dams adjacent the ends of the nip to confine said casting pool;
• c) a casting roll drive capable of counter-rotating the casting rolls to form metal shells on casting surfaces of the casting rolls and cast solidified thin steel strip through the nip between the casting rolls from said metal shells;
• d) a plurality of preheating chambers removed from an operating position for casting capable of preheating at least a portion of at least one refractory component to be used as a replacement selected from the group consisting of a second core nozzle and a second tundish to a temperature to avoid thermal shock when contacted by molten steel while casting continues;
• e) a gate capable of interrupting the flow of molten metal to the casting pool, and capable of resuming flow of molten steel to reform the casting pool;
• f) a first transfer device capable of rapidly removing from an operating position at least portions of at least one component selected from the group consisting of at least a portion of the first core nozzle and the first tundish desired to be replaced while leaving the first side dams in the operating position;
• and
• g) a second transfer device capable of rapidly transferring at least portions of at least one preheated component selected from the group consisting of the second core nozzle and the second tundish for replacement from the preheating chamber to the operating position for casting while leaving the first side dams in the operating position.