Thin roll strip caster and method of operating the same

Abstract

A method of casting a thin strip is disclosed. The method includes assembling a pair of side dams adjacent end portions of counter-rotating casting rolls through which a strip of metal can be cast to permit a casting pool of molten metal to be formed supported by the casting surfaces of the casting rolls, assembling a metal delivery system above the casting rolls delivering molten metal to form a casting pool supported on the casting surfaces of the casting rolls above the nip and confined by the pair of side dams, assembling a mechanical screw drive to move axially the side dams toward the casting pool, counter-rotating the casting rolls such that the casting surfaces of the casting rolls each travel inwardly to produce a cast strip downwardly from the nip, and moving the side dams axially inward toward the casting pool at a rate of between 0.4 and 5.0 mm/hour by actuation of the mechanical screw.

What is claimed is: 
     
         1 . A method of casting thin strip comprising the steps of:
 assembling a pair of counter-rotating casting rolls laterally forming a nip between circumferential casting surfaces of the rolls through which metal strip can be cast,   assembling a pair of side dams adjacent end portions of the casting roll to permit a casting pool of molten metal to be formed supported by the casting surfaces of the casting rolls,   assembling a metal delivery system above the casting rolls delivering molten metal to form a casting pool supported on the casting surfaces of the casting rolls above the nip and confined by the pair of side dams,   assembling a mechanical screw drive to move axially the side dams toward the casting pool,   counter-rotating the casting rolls such that the casting surfaces of the casting rolls each travel inwardly toward the nip to produce a cast strip downwardly from the nip, and   moving the side dams axially inward toward the casting pool at a rate of between 0.4 and 5.0 mm/hour by actuation of the mechanical screw.   
     
     
         2 . The method of casting thin strip as claimed in  claim 1  comprising in addition a sensor to measure wear rate of the said dams, and actuating the mechanical screw to automatically to move the side dams inwardly toward the casting pool in response to the measured wear rate exerted on the side dams . 
     
     
         3 . The method of casting thin strip as claimed in  claim 1  where the mechanical screw moves at a continuous rate inwardly toward the casting pool. 
     
     
         4 . The method of casting thin strip as claimed in  claim 1  where the mechanical screw moves at a variable rate inwardly toward the casting pool. 
     
     
         5 . The method of casting thin strip as claimed in  claim 1  where the mechanical screw moves at a rate of between 1.0 and 2.5 mm/hour. 
     
     
         6 . The method of casting thin strip as claimed in  claim 1  comprising in addition a sensor to measure force exerted on the said dams, and actuating the mechanical screw to automatically to move the side dams inwardly toward the casting pool in response to the measured force exerted on the side dams . 
     
     
         7 . A thin roll strip caster comprising:
 a pair of counter-rotating casting rolls laterally forming a nip between circumferential casting surfaces of the rolls through which metal strip can be cast;   a pair of side dams adjacent end portions of the casting roll to permit a casting pool of molten metal to be formed supported by the casting surfaces of the casting rolls;   a metal delivery system above the casting rolls delivering molten metal to form a casting pool supported on the casting surfaces of the casting rolls above the nip and confined by the pair of side dams; and   a mechanical screw drive for moving axially the side dams inward toward the casting pool at a rate of between 0.4 and 5.0 mm/hour by actuation of the mechanical screw,   wherein the casting rolls may be counter-rotated such that the casting surfaces of the casting rolls each travel inwardly toward the nip to produce a cast strip downwardly from the nip.   
     
     
         8 . The thin strip caster as claimed in  claim 7  where the side dams are moved axially inward toward the casting pool at a rate between 1.0 and 2.5 mm/hour. 
     
     
         9 . The thin strip caster as claimed in  claim 7  where the mechanical screw moves at a continuous rate. 
     
     
         10 . The thin strip caster as claimed in  claim 7  where the mechanical screw moves at a variable rate. 
     
     
         11 . The thin strip caster as claimed in  claim 7  further comprising a sensor for detecting the position of the side dam. 
     
     
         12 . The thin strip caster as claimed in  claim 7  wherein the sensor communicates with the mechanical screw drive to adjust the position of the side dam. 
     
     
         13 . The thin strip caster as claimed in  claim 12  where the sensor is a position sensor. 
     
     
         14 . The thin strip caster as claimed in  claim 12  where the sensor is a force sensor. 
     
     
         15 . The thin strip caster as claimed in  claim 12  comprising a sensor on each side dam. 
     
     
         16 . The thin strip caster as claimed in  claim 15  where the side dams move independently. 
     
     
         17 . The thin strip caster as claimed in  claim 15  where the side dams move together.