Process for producing a steel strip

Abstract

A process for producing a strip-cast, low-carbon, partly Mn/Si killed steel strip which is largely free of cracks and surface defects from a steel melt having a sulfur content of between 20 and 300 ppm and an Mn/Si ratio ≧3.5, using a roll separating force of between 2 and 50 kN/m.

1 . A process for producing a strip-cast, low-carbon, partly Mn/Si killed steel strip, comprising
 introducing a steel melt between at least two casting rolls that are cooled and that move together with a steel strip, such that the steel strip at least partly solidifies on the casting rolls to form the steel strip, and   selecting the steel melt with a sulfur content of between 20 and 300 ppm and an Mn/Si ratio ≧3.5 and, during normal operation, applying a roll separating force at the casting rolls of between 2 and 50 kN/m.   
     
     
         2 . The process as claimed in  claim 1 , wherein the steel melt has a sulfur content of between 50 and 250 ppm. 
     
     
         3 . The process as claimed in  claim 1 , wherein the roll separating force is between 5 and 30 kN/m. 
     
     
         4 . The process as claimed in  claim 1 , wherein the steel melt contains non-metallic inclusions with a mass fraction Al 2 O 3  of less than 45% by weight. 
     
     
         5 . The process as claimed in  claim 1 , wherein the steel melt has a sulfur content of between 70 and 200 ppm.