Method of controlling the formation of crocodile skin surface roughness on thin cast strip

A method of controlling the formation of crocodile skin surface roughness in continuous casting of thin cast strip of plain carbon steel comprising the steps of:

• assembling a pair of counter-rotating casting rolls laterally to form a nip between circumferential casting surfaces of the rolls through which metal strip may be cast;
• forming a casting pool of molten metal of less than 0.65% by weight carbon supported on the casting surfaces of the casting rolls above the nip;
• assembling a rotating brush peripherally to contact the casting surface of each casting roll in advance of contact of the casting surfaces with the molten metal;
• forming at least one clean band with a majority of projections on the casting surfaces exposed to provide as reference for controlling the pressure exuded by the rotating brushes against the casting surfaces of the casting rolls;
• controlling the energy of the rotating brush against the casting rolls using the clean band as a reference;
• and
• counter-rotating the casting rolls such that the casting surfaces of the casting rolls each travel toward the nip to produce a cast strip downwardly from the nip.

A method of controlling the formation of crocodile skin surface roughness in continuous casting of thin cast strip of plain carbon steel comprising the steps of:

• assembling a pair of counter-rotating casting rolls laterally to form a nip between circumferential casting surfaces of the rolls through which metal strip may be cast;
• forming a casting pool of molten metal of plain carbon steel of less than 0.65% by weight carbon supported on the casting surfaces of the casting rolls above the nip;
• assembling a rotating brush peripherally to contact the casting surface of each casting roll in advance of contact of the casting surfaces with the molten metal capable of cleaning residual from the surface of the casting roll;
• cleaning to expose a majority of projections of the casting surfaces of the casting rolls and measuring the heat flux from molten metal with the cleaned casting surfaces;
• continually measuring the heat flux from the molten metal to the casting surfaces of the casting rolls;
• controlling the energy of the rotating brush against the casting surface of the casting roll based on the difference between said measured heat flux and an initially measured heat flux between the molten metal and the casting surface;
• and
• counter-rotating the casting rolls such that the casting surfaces of the casting rolls each travel toward the nip to produce a cast strip downwardly from the nip.