Rolls for disposing at entry side or exit side of quenching zone of continuous annealing furnace and quenching zone unit using rolls

Abstract

A roll that can be disposed before and/or after a quenching zone of a continuous annealing furnace is provided. The roll has a predetermined profile satisfying Lc≧0.7×W min ; R=−0.1×10 −3 to +0.2×10 −3 ; and TR≧20, wherein Lc represents the length (mm) of a flat portion in the center of the roll, W min represents the minimum width (mm) of a steel strip, R represents the inclination of tapered portions disposed at two sides of the roll, and TR represents the radius of curvature (m) of boundaries between the flat portion and the tapered portions. The roll can be used as a hearth roll and/or a bridle roll disposed at the entry side and/or the exit side of the quenching zone.

What is claimed is:  
     
         1 . A roll for disposing at an entry side or an exit side of a quenching zone of a continuous annealing furnace, the roll satisfying the following relationships: 
 Lc≧0.7×W min ;    R=−0.1×10 −3  to +0.2×10 −3 ; and    TR≧20    wherein Lc represents a length (mm) of a flat portion in the center of the roll,    W min  represents a minimum width (mm) of a steel strip,    R represents the inclination of tapered portions disposed at two sides of the roll, and    TR represents the radius of curvature (m) of boundaries between the flat portion and the tapered portions.    
     
     
         2 . A quenching zone unit of a continuous annealing furnace, comprising: 
 a quenching zone having an entry side and an exit side; and    at least one roll selected from the group consisting of hearth rolls and bridle rolls disposed at at least one of the entry side and the exit side of the quenching zone,    wherein the at least one roll comprises the roll according to  claim 1 .    
     
     
         3 . A quenching zone unit of a continuous annealing furnace, comprising: 
 a quenching zone having an entry side and an exit side; and    at least one bridle roll unit comprising a plurality of rolls, the at least one bridle roll unit being disposed at at least one of the entry side and the exit side of the quenching zone,    wherein each of the plurality of rolls comprises the roll according to  claim 1 .    
     
     
         4 . The quenching zone unit of a continuous annealing furnace according to  claim 3 , wherein a roll of the plurality of rolls that is closest to the quenching zone is a flat roll satisfying the relationships (i) R=0 and (ii) TR=∞.  
     
     
         5 . The quenching zone unit of a continuous annealing furnace according to  claim 2 , comprising at least one pair of seal rolls disposed at at least one of the entry side and the exit side of the quenching zone.  
     
     
         6 . The quenching zone unit of a continuous annealing furnace according to  claim 3 , comprising at least one pair of seal rolls disposed at at least one of the entry side and the exit side of the quenching zone.  
     
     
         7 . The quenching zone unit of a continuous annealing furnace according to  claim 4 , comprising at least one pair of seal rolls disposed at at least one of the entry side and the exit side of the quenching zone.