Method and apparatus for controlling strip shape in hot rolling mills

A method of producing thin cast strip with controlled strip irregularities in the shape by continuous casting comprising the steps of:

• a. assembling a thin strip caster having a pair of casting rolls having a nip there between;
• b. assembling a metal delivery system capable of forming a casting pool between the casting rolls above the nip with side dams adjacent the ends of the nip to confine said casting pool;
• c. assembling adjacent the thin strip caster a hot rolling mill having work rolls with work surfaces forming a gap between them through which hot strip is rolled, said work rolls having work roll surfaces relating to a desired strip profile across the work rolls;
• d. assembling spray nozzles positioned at intervals along the work rolls of the hot rolling mill in at least three lateral zones, a central and two edge zones, and capable of spraying coolant in each zone with the flow volume of coolant sprayed by the nozzle(s) in each zone being capable of being individually controlled;
• e. assembling a control system capable of individually regulating the flow of coolant from at least some of the spray nozzles in each zone onto the work surface of each work roll being sprayed;
• f. 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 side dams;
• g. 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;
• and
• h. rolling the thin cast strip between the work rolls of the hot rolling mill and varying the flow of coolant to at least one of the nozzles in each zone so as to control, the shape of the work surface of at least one work roll and control strip irregularities occurring in any zone in the thin cast strip.