Non-Oriented Electrical Steel Having High Magnetic Induction And High Intensity And Manufacturing Method Thereof

Abstract

A non-oriented electrical steel has relative high magnetic induction and high intensity without increasing manufacturing difficulty. The weight percentage of the compositions of the electrical steel are as follows: C≦0.0040%, Si is 2.50% to 4.00%, Al is 0.20% to 0.80%, Cr is 1.0 to 8.0%, Ni is 0.5 to 5.0%, Mn≦0.50%, P≦0.30%, S≦0.0020%, N≦0.0030%, Ti≦0.0030%, Nb≦0.010%, V≦0.010%, C+S+N+Ti≦0.010%, and a balance substantially being Fe and inevitable impurities.

1 . A non-oriented electrical steel having relative high magnetic induction and high intensity, said steel comprising by weight percentage:
 C: ≦0.0040%;   Si: 2.50%˜4.00%;   Al: 0.20%˜0.80%;   Cr: 1.0˜8.0%;   Ni: 0.5˜5.0%;   Mn: ≦0.50%;   P: ≦0.30%;   S: ≦0.0020%;   N: ≦0.0030%;   Ti: ≦0.0030%;   Nb: ≦0.010%;   V: ≦0.010%;   C+S+N+Ti: ≦0.010%;   
       and a balance substantially being Fe and inevitable impurities. 
     
     
         2 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , including Cu≦3%, as represented by weight percentage. 
     
     
         3 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , including at least one of Sb and Sn with a total content of no more than 0.5%, as represented by weight percentage. 
     
     
         4 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , including at least one of C≦0.002% and C≦0.0015%, as represented by weight percentage. 
     
     
         5 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of Si of 2.8 to 3.3%, as represented by weight percentage. 
     
     
         6 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of Al of 0.4% to 0.6%, as represented by weight percentage. 
     
     
         7 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of Cr of 2.5% to 6%, as represented by weight percentage. 
     
     
         8 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of Ni of 1.0% to 3.5%, as represented by weight percentage. 
     
     
         9 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of P of no more than 0.1%, and a content of S of no more than 0.0015%, as represented by weight percentage. 
     
     
         10 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of N of no more than 0.002%, as represented by weight percentage. 
     
     
         11 . The non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 1 , having a content of Ti of no more than 0.0015%, as represented by weight percentage. 
     
     
         12 . A method for manufacturing a non-oriented electrical steel having relative high magnetic induction and high intensity, comprising the steps of:
 1) smelting a non-oriented electrical steel having a chemical composition by weight percent of C≦0.0040%, Si is 2.50%∞4.00%, Al is 0.20%˜0.80%, Cr is 1.0˜8.0%, Ni is 0.5˜5.0%, Mn≦0.50%, P≦0.30%, S≦0.0020%, N≦0.0030%, Ti≦0.0030%, Nb≦0.010%, V≦0.010%, C+S+N+Ti≦0.010%, and a balance substantially being Fe and inevitable impurities;   2) forming the non-oriented electrical steel into a slab using a RH vacuum process;   3) hot rolling the slab at a heating temperature of the slab is 1050° C. to 1200° C. to form a hot rolled plate, wherein a holding time is no less than 30 min, incipient rolling temperature in a planishing process is controlled to 940° C. to 1000° C. , end-rolling temperature is no less than 850° C., final stand screw-down rate is controlled to 10 to 15%, a coiling temperature is controlled to 500 to 700° C., and a thickness of the rolled plate is 2.0 to 2.6 mm;   4) normalizing the hot rolled plate to form a normalized plate, wherein a normalizing temperature is 850 to 950° C., with a holding time is 0.5 to 3 min, the hot rolled plate is then cooled to 650 to 750° C. at a cooling speed of 5 to 15° C./s, and then further cooled to no higher than 100° C. at a cooling speed of 20 to 70° C./s;   5) acid pickling the normalized plate to form a pickled normalized plate;   6) cold rolling the pickled normalized plate, wherein said pickled normalized plate is cold rolled using a single cold rolled process with a total screw-down rate is no less than 70%; and   7) annealing the cold rolled pickled normalized plate by carrying out an annealing treatment with a continuous furnace, wherein said annealing treatment includes heating said plate at an annealing temperature of 800° C. to 1000° C. for a period of 5 s to 60 s, then cooling the plate to 650° C. to 750° C. at a cooling speed of 3 to 10° C./s, and then further cooling the plate to no higher than 100° C. at a cooling speed of 20 to 70° C./s.   
     
     
         13 . The method for manufacturing a non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 12 , in which the non-oriented electrical steel further comprising Cu≦3%, as represented by weight percentage. 
     
     
         14 . The method for manufacturing a non-oriented electrical steel having relative high magnetic induction and high intensity in  claim 12 , in which the non-oriented electrical steel further comprising Sb and/or Sn, having a total content of no more than 0.5%, as represented by weight percentage.