Facility and method for cold rolling metal strip

Abstract

In a facility for cold rolling a metal strip in a circulating oil-feeding system by jetting a low concentration coolant, in a neighborhood of an inlet side of a work roll and jetting a high concentration coolant at an upstream side of the jetting position of the low concentration coolant to conduct rolling, the metal strip is cold rolled with the cold rolling facility provided with a control equipment for varying a jetting amount of the low concentration coolant in accordance with a rolling rate so that a tip of a liquid pool of the low concentration coolant formed on a surface of a steel sheet at an inlet side of the work roll does not reach a jetting position of the high concentration coolant, whereby the rolling can be performed without losing a plate-out property even if the rolling rate is decreased.

1 . A facility for cold rolling a metal strip in a circulating oil-feeding system by jetting a low concentration coolant in a neighborhood of an inlet side of a work roll and jetting a high concentration coolant at an upstream side of a jetting position for the low concentration coolant to conduct rolling,
 characterized in that the facility is provided with a control equipment for varying a jetting amount of the low concentration coolant in accordance with a rolling rate so that a tip of a liquid pool of the low concentration coolant formed on a surface of a steel sheet at an inlet side of the work roll does not reach a jetting position of the high concentration coolant.   
     
     
         2 . The facility for cold rolling a metal strip according to  claim 1 , which is provided with a control equipment for varying a jetting amount of the high concentration coolant in accordance with the rolling rate. 
     
     
         3 . The facility for cold rolling a metal strip according to  claim 1 , wherein a concentration of a rolling oil in the low concentration coolant is 2-4 mass % and a concentration of a rolling oil in the high concentration coolant is 10-15 mass %. 
     
     
         4 . A method for cold rolling a metal strip with a cold rolling facility in a circulating oil-feeding system by jetting a low concentration coolant in a neighborhood of an inlet side of a work roll and jetting a high concentration coolant at an upstream side of a jetting position of the low concentration coolant to conduct rolling,
 characterized in that a jetting amount of the low concentration coolant is varied in accordance with a rolling rate so that a tip of a liquid pool of the low concentration coolant formed on a sheet surface at an inlet side of the work roll does not reach a jetting position of the high concentration coolant.   
     
     
         5 . The method for cold rolling a metal strip according to  claim 4 , wherein a jetting amount of the high concentration coolant is varied in accordance with the rolling rate. 
     
     
         6 . The method for cold rolling a metal strip according to  claim 4 , wherein a concentration of a rolling oil in the low concentration coolant is 2-4 mass % and a concentration of a rolling oil in the high concentration coolant is 10-15 mass %. 
     
     
         7 . The facility for cold rolling a metal strip according to  claim 2 , wherein a concentration of a rolling oil in the low concentration coolant is 2-4 mass % and a concentration of a rolling oil in the high concentration coolant is 10-15 mass %. 
     
     
         8 . The method for cold rolling a metal strip according to  claim 5 , wherein a concentration of a rolling oil in the low concentration coolant is 2-4 mass % and a concentration of a rolling oil in the high concentration coolant is 10-15 mass %.