Non-oriented electrical steel plate without corrugated fault and production method thereof

Abstract

A non-oriented electrical steel sheet without corrugated defect and a manufacturing method thereof is provided, the weight percentage of the chemical composition of the non-oriented electrical steel sheet is that C is no more than 0.005%, Si is 1.2-2.2%, Mn is 0.2-0.4%, P is no more than 0.2%, S is no more than 0.005%, Al is 0.2-0.6%, N is no more than 0.005%, O is no more than 0.005%, and a balance substantially being Fe, a slab can be obtained by hot metal preprocessing, smelting with converter, RH refining, and continuous casting and pouring, wherein a secondary cooling water amount is controlled, the water flowrate of cooling water is controlled to 100-190 l/min, the average superheat of liquid steel in the continuous casting process is controlled to 10-45° C., the slab is heated and hot rolled; wherein the furnace tap temperature of the slab is 1050-1150 ° C., the temperature difference between random two points in the length direction when the slab is heated, is lower than 25° C., the hot rolling process includes a rough rolling process and a planishing process, the entry temperature in the planishing process is no lower than 970° C.; the finished non-oriented electrical steel sheet is obtained by acid pickling, cold rolling, annealing and coating. No corrugated defect can be accomplished by controlling the cooling speed of the slab in continuous casting and pouring process, the temperature difference in the length direction of the slab in the heating furnace, and by controlling the temperature drop before planishing the slab.

1 . A non-oriented electrical steel sheet without corrugated defect, wherein the weight percentage of the chemical composition thereof is that C<0.005%, Si is 1.2-2.2%, Mn is 0.2-0.4%, P<0.2%, S<0.005%, Al is 0.2-0.6%, N<0.005%, O<0.005%, and a balance substantially being Fe and inevitable impurities. 
     
     
         2 . A method for manufacturing a non-oriented electrical steel sheet without corrugated defect, said method comprising the following steps:
 continuously casting a slab of steel having a weight percentage chemical composition including C<0.005%, Si is 1.2-2.2%, Mn is 0.2-0.4%, P<0.2%, S<0.005%, Al is 0.2-0.6%, N<0.005%, O<0.005%, and a balance substantially being Fe and inevitable impurities, wherein water flowrate of cooling water is controlled to 100-190 l/min, and an average superheat of liquid steel during the continuous casting is controlled to 10-45° C.;
 maintaining a furnace tap temperature of the slab at 1050-1150° C.; 
 maintaining a temperature difference between two random points in a length direction when the slab is heated lower than 25° C.; 
 hot rolling the slab wherein hot rolling includes a rough rolling process; 
 planishing the slab, wherein an entry temperature in the planishing is no lower than 970° C.; and 
   acid pickling, cold rolling, annealing, and/or coating the slab to obtain the finished non-oriented electrical steel sheet.