Method of producing non-oriented electrical steel sheet

Abstract

Disclosed is a method for producing a non-oriented magnetic steel sheet, wherein a steel slab that consists of 0.01-0.1 mass % of C, 4 mass % or less of Si, 0.05-3 mass % of Mn, 3 mass % or less of Al, 0.005 mass % or less of S, 0.005 mass % or less of N and the balance made up of Fe and unavoidable impurities is subjected to hot rolling, cold rolling and final annealing. By carrying out the final annealing, while setting the average heating rate during the heating to 100° C./sec or more and setting the soaking temperature within the temperature range of 750-1100° C., a non-oriented magnetic steel sheet that has extremely increased magnetic flux density in the rolling direction of the steel sheet is advantageously produced.

1 . A method of producing a non-oriented electrical steel sheet by subjecting a steel slab comprising C: 0.01-0.1 mass %, Si: not more than 4 mass %, Mn: 0.05-3 mass %, Al: not more than 3 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass % and the remainder being Fe and inevitable impurities to hot rolling, cold rolling and finish annealing, characterized in that the finish annealing is conducted under conditions that an average temperature rising rate during the heating is not less than 100° C./sec and a soaking temperature is a temperature range of 750-1100° C. 
     
     
         2 . A method of producing a non-oriented electrical steel sheet according to  claim 1 , wherein the steel slab further contains at least one of Sn and Sb in an amount of 0.005-0.1 mass %, respectively. 
     
     
         3 . A method of producing a non-oriented electrical steel sheet according to  claim 1 , wherein decarburization annealing is conducted after the finish annealing. 
     
     
         4 . A method of producing a non-oriented electrical steel sheet according to  claim 2 , wherein decarburization annealing is conducted after the finish annealing.