Manufacture Process Of Non-Oriented Silicon Steel With High Magnetic Induction

Abstract

A manufacture process of non-oriented silicon steel with high magnetic induction includes smelting and casting steel having a chemical composition by weight percent: Si 0.1˜1%, Al 0.005˜1.0%, C≦0.004%, Mn=0.10˜1.50%, P≦0.2%, S≦0.005%, N≦0.002, Nb+V+Ti≦0.006%, and the rest is Fe. The steel is cast into a billet, which is heated and hot-rolled to 1150˜1200° C. into a plate at a finish-rolling temperature 830˜900° C. The plate is cooled to a temperature ≧570° C. and cold-roll flattened at compression ratio 2˜5%. The flattened plate is normalized at temperature not below 950° C. for 30˜180s, and then pickled and cold-rolled into a sheet with thickness of the finished product. The sheet is finish-annealed quickly heating the sheet to 800˜1000° C. at temperature rise rate ≧100° C./s, soaking the heated sheet for 5˜60s at the temperature, and then slowly cooling the sheet to 600˜750° C.

1 . A manufacture process of non-oriented silicon Steel with high magnetic induction comprising the following procedures:
 smelting a non-oriented silicon steel having the following chemical compositions by weight percent: Si 0.1˜1%, Al 0.005˜1.0%, C≦0.004%, Mn 0.10˜1.50%, P≦0.2%, S≦0.005%, N≦0.002, Nb+V+Ti≦0.006%, and the rest is Fe and unavoidable inclusions;   casting the non-oriented silicon steel into a steel billet;   heating the steel billet to a temperature between 1150˜1200° C.;   heat soaking the heated steel billet at the temperature for a certain time;   hot-rolling the heat soaked steel billet into a steel plate at a finish-rolling temperature of 830˜900° C.;   cooling the steel plate to a temperature ≧570° C.;   cold-rolling the cooled steel plate at rolling compression ratio of 2˜5%;   after being cold-rolled, continuously normalizing the steel plate at one time at a temperature not below 950° C., and maintained at the temperature for 30˜180s;   pickling the normalized steel plate;   cold-rolling the pickled normalized steel plate several times into a cold-rolled sheet having a predetermined thickness at a total rolling compression ratio of 70˜80%; and   heat-annealing the cold-rolled sheet, wherein a temperature rise rate of the cold-rolled sheet is not below 100° C./s, the temperature of the cold-rolled sheet is raised to between 800˜1000° C., maintained at the temperature for 5˜60s, and thereafter, cooled to 600˜750° C. at a cooling rate of 3˜15° C./s.   
     
     
         2 . The manufacture process of non-oriented silicon Steel with high magnetic induction as defined in  claim 1 , in which heat-annealing the cold-rolled sheet is conducted in an atmosphere which is, by volume percent, H 2  of 30%˜70%+N 2  of 70%˜30%, and a dew point ≦−25° C.