Continuously casting steel strip

A method of producing thin cast strip by continuous casting comprising the steps of:

• a) assembling a pair of casting rolls having a nip therebetween;
• b) assembling 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) introducing molten steel between the pair of casting rolls to form a casting pool supported on casting surfaces of the casting rolls confined by said first side dams;
• d) counter-rotating 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;
• e) commencing preheating, while casting, in at least one preheating positions removed from an operating position for casting at least portions of at least one side dam of second side dams to he used as a replacement to a temperature to avoid thermal shock when contacted by molten steel while casting;
• f) interrupting the flow of molten metal to the casting pool and allowing the casting pool to drain;
• g) removing rapidly from an operating position at least portions of at least one of the first side dams desired to be replaced;
• h) transferring rapidly at least portions of at least one preheated second side dam to be used as a replacement from the preheating position to the operating position for casting to replace the removed first side dam or portions thereof without removing other refractory components from the operating position, and
• i) resuming flow of molten steel to reform the casting pool and resume casting of strip.

A method of producing thin cast strip by continuous casting comprising the steps of:

• a) assembling a pair of casting rolls having a nip therebetween;
• b) assembling 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) introducing molten steel between the pair of casting rolls to form a casting pool supported on casting surfaces of the casting rolls confined by said first side dams;
• d) counter-rotating the casting rolls to form solidified metal shells on the surfaces of the casting rolls and cast thin steel strip through the nip between the casting rolls from said solidified shells;
• e) commencing preheating, while casting, in at least one preheating position removed from an operating position for casting at least portions of at least one refractory component 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;
• f) interrupting the flow of molten metal to the casting pool and allowing the casting pool to drain;
• g) removing rapidly from an operating position at least portions of at least one component selected from the group consisting of the first core nozzle and the first tundish desired to be replaced;
• h) transferring rapidly at least portions of at least one preheated refractory component to be used as a replacement selected from the group consisting of said second core nozzle and second tundish from the preheating position to the operating position for casting to replace the removed refractory component or portions thereof without removing other refractory components from the operating position, and
• i) resuming flow of molten steel to reform the casting pool and resuming casting of thin cast strip.