Side dam with insert

Abstract

A composite side dam for a continuous twin roll caster includes a substrate made of a refractory material capable of withstanding casting temperature and having edge portions adapted to engage casting rolls and having a nip portion adjacent a nip between casting rolls and upper portions extending across the side dam to form a lateral restraint for a casting pool, an insert of at least 10 mm in thickness positioned in a pocket in the substrate and extending to engage the molten metal and extending from the upper portions of the substrate and positioned in the pocket to within 30 mm from the nip portion by insertion adjacent the upper portions of the substrate, and the insert adapted to fit into the pocket of the substrate to form a side dam formed of a refractory material having consumption rate less than 10 mm per hour. The material forming the insert may be between 40 and 60% SiAlON material and the remainder hBN material, or mullite material as described by FIG. 11, or between about 60 and 63 mole percent Al 2 O 3 and the remainder SiO 2 , or fused silica, such as between 40 and 60% fused SiO 2 and the remainder hBN material.

What is claimed is: 
     
         1 . A composite side dam for a continuous twin roll caster comprising:
 (a) a substrate shaped to form a side dam and made of a refractory material capable of withstanding casting temperature in a twin roll caster and having edge portions adapted to engage end portions of casting rolls and having a nip portion adapted to be adjacent a nip between casting rolls and upper portions extending across the side dam to form a lateral restraint for a casting pool of molten metal during operation in a twin roll caster,   (b) an insert of at least 10 mm in thickness positioned in a pocket in the substrate and extending to engage the molten metal in operation of a twin roll caster and extending from the upper portions of the substrate such that the insert can be positioned in the pocket to within 30 mm from the nip portion of the substrate by insertion adjacent the upper portions of the substrate to engage end portions of the casting rolls during operation of the twin roll caster, and   (c) the insert adapted to fit into the pocket of the substrate to form a side dam formed of a refractory material having consumption rate less than 10 mm per hour.   
     
     
         2 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the material forming the insert is comprised of SiAlON material. 
     
     
         3 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the material forming the insert is between 40 and 60% SiAlON material and the remainder hBN material. 
     
     
         4 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the material forming the insert is comprised of mullite material as described by  FIG. 11 . 
     
     
         5 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the material forming the insert is between about 60 and 63 mole percent Al 2 O 3  and the remainder SiO 2 . 
     
     
         6 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the material forming the insert is comprised of fused silica material. 
     
     
         7 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the material forming the insert is between 40 and 60% fused SiO 2  and the remainder hBN material. 
     
     
         8 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the consumption rate of the refractory material forming the insert is at least as great as the wear rate of said material. 
     
     
         9 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the insert is between 10 mm and 40 mm in thickness. 
     
     
         10 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the insert is between 10 mm and 40 mm in thickness. 
     
     
         11 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the insert is between 10 mm and 40 mm in thickness. 
     
     
         12 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the insert is between 10 mm and 40 mm in thickness. 
     
     
         13 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the insert is a firm fit positioned in the pocket. 
     
     
         14 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the insert is a firm fit positioned in the pocket. 
     
     
         15 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the insert is a firm fit positioned in the pocket. 
     
     
         16 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the insert is a firm fit positioned in the pocket. 
     
     
         17 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         18 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         19 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         20 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         21 . The composite side dam for a continuous twin roll caster as claimed in  claim 13  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         22 . The composite side dam for a continuous twin roll caster as claimed in  claim 14  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         23 . The composite side dam for a continuous twin roll caster as claimed in  claim 15  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         24 . The composite side dam for a continuous twin roll caster as claimed in  claim 16  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         25 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the insert is positioned in the pocket with a ceramic cement. 
     
     
         26 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the insert is positioned in the pocket with a ceramic cement. 
     
     
         27 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the insert is positioned in the pocket with a ceramic cement. 
     
     
         28 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the insert is positioned in the pocket with a ceramic cement. 
     
     
         29 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the thickness of the insert is greater than depth of the pocket. 
     
     
         30 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the thickness of the insert is greater than depth of the pocket. 
     
     
         31 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the thickness of the insert is greater than depth of the pocket. 
     
     
         32 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the thickness of the insert is greater than depth of the pocket. 
     
     
         33 . The composite side dam for a continuous twin roll caster as claimed in  claim 1  where the insert extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         34 . The composite side dam for a continuous twin roll caster as claimed in  claim 2  where the insert extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         35 . The composite side dam for a continuous twin roll caster as claimed in  claim 4  where the insert extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         36 . The composite side dam for a continuous twin roll caster as claimed in  claim 6  where the insert extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         37 . Apparatus for continuously casting metal strip comprising:
 (a) a pair of counter-rotatable casting rolls laterally positioned to form a nip there between through which thin strip can be cast,   (b) a pair of confining side dams adjacent the ends of the casting rolls capable of confining a casting pool of molten metal supported on the casting rolls and formed on the casting surfaces above the nip,   (c) each side dam is a composite comprising a substrate made of a refractory material capable of withstanding casting temperature and extending from the upper portions of the substrate to a nip portion adapted to be adjacent a nip between casting rolls and such that the insert can be positioned in the pocket by insertion adjacent the upper portions of the substrate to engage end portions of the casting rolls to within 30 mm from the nip portion of the substrate during operation of the twin roll caster, and an insert of at least 10 mm in thickness positioned in a pocket in the substrate and extending to engage the molten metal and the end portions of the casting rolls in operation of the twin roll caster, and the insert adapted to fitted into the pocket of the substrate to form the side dam formed of a material having a consumption rate less than 10 mm per hour, and   (d) a metal delivery system disposed above the nip and capable of discharging molten metal to form the casting pool supported on the casting rolls.   
     
     
         38 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert of the substrate is comprised of SiAlON material. 
     
     
         39 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert of the substrate is between 40 and 60% SiAlON material and the remainder hBN material. 
     
     
         40 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert is mullite material as defined by  FIG. 11 . 
     
     
         41 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert between about 60 and 63 mole percent Al 2 O 3  and the remainder SiO 2 . 
     
     
         42 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert of the substrate is comprised of fused silica material. 
     
     
         43 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the material forming the insert of the substrate is between 40 and 60% fused SiO 2  and remainder hBN material. 
     
     
         44 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the consumption rate of the refractory material forming the insert is at least as great as the wear rate of said material. 
     
     
         45 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the insert of the substrate is between 10 mm and 40 mm in thickness. 
     
     
         46 . The apparatus for continuously casting metal strip as claimed in  claim 38  where the insert of the substrate is between 10 mm and 40 mm in thickness. 
     
     
         47 . The apparatus for continuously casting metal strip as claimed in  claim 40  where the insert of the substrate is between 10 mm and 40 mm in thickness. 
     
     
         48 . The apparatus for continuously casting metal strip as claimed in  claim 42  where the insert of the substrate is between 10 mm and 40 mm in thickness. 
     
     
         49 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the insert is a firm fit positioned in the pocket of the substrate. 
     
     
         50 . The apparatus for continuously casting metal strip as claimed in  claim 38  where the insert is a firm fit positioned in the pocket of the substrate. 
     
     
         51 . The apparatus for continuously casting metal strip as claimed in  claim 40  where the insert is a firm fit positioned in the pocket of the substrate. 
     
     
         52 . The apparatus for continuously casting metal strip as claimed in  claim 42  where the insert is a firm fit positioned in the pocket of the substrate. 
     
     
         53 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         54 . The apparatus for continuously casting metal strip as claimed in  claim 38  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         55 . The apparatus for continuously casting metal strip as claimed in  claim 40  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         56 . The apparatus for continuously casting metal strip as claimed in  claim 49  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         57 . The apparatus for continuously casting metal strip as claimed in  claim 50  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         58 . The apparatus for continuously casting metal strip as claimed in  claim 51  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         59 . The apparatus for continuously casting metal strip as claimed in  claim 55  where the insert has edge portions of a reverse angle of at least 3° to engage edge portions of the pocket in the substrate. 
     
     
         60 . The apparatus for continuously casting metal strip composite side dam as claimed in  claim 37  where the insert of the substrate is positioned in the pocket with a ceramic cement. 
     
     
         61 . The apparatus for continuously casting metal strip as claimed in  claim 38  where the insert of the substrate is positioned in the pocket with a ceramic cement. 
     
     
         62 . The apparatus for continuously casting metal strip as claimed in  claim 40  where the insert of the substrate is positioned in the pocket with a ceramic cement. 
     
     
         63 . The apparatus for continuously casting metal strip as claimed in  claim 42  where the insert of the substrate is positioned in the pocket with a ceramic cement. 
     
     
         64 . The apparatus for continuously casting metal strip as claimed in  claim 37  where the thickness of the insert of the substrate is greater than depth of the pocket. 
     
     
         65 . The apparatus for continuously casting metal strip as claimed in  claim 38  where the thickness of the insert of the substrate is greater than depth of the pocket. 
     
     
         66 . The apparatus for continuously casting metal strip as claimed in  claim 40  where the thickness of the insert of the substrate is greater than depth of the pocket. 
     
     
         67 . The apparatus for continuously casting metal strip as claimed in  claim 42  where the thickness of the insert of the substrate is greater than depth of the pocket. 
     
     
         68 . The apparatus for continuously casting metal as claimed in  claim 37  where the insert of the substrate extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         69 . The apparatus for continuously casting metal as claimed in  claim 38  where the insert of the substrate extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         70 . The apparatus for continuously casting metal as claimed in  claim 40  where the insert of the substrate extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam. 
     
     
         71 . The apparatus for continuously casting metal as claimed in  claim 42  where the insert of the substrate extends toward the nip portion to allow at least a 2.5 mm radius in the insert adjacent nip portions of the side dam.