Electrical steel processing without a post cold-rolling intermediate anneal

Abstract

Embodiments of the present invention comprise; annealing steel sheets (e.g., hot rolled steel sheets or thin cast strip steel); cold rolling the sheets in one or more cold rolling steps (e.g., with annealing steps between multiple cold rolling steps); and performing one or more of tension leveling, a rough rolling, or a coating process on the sheets after cold rolling, without an intermediate annealing step between the final cold rolling step and the tension leveling, the rough rolling, or the coating process, or the customer stamping or final customer annealing. In order to achieve the desired properties for the steel sheet, stamping and final annealing is performed by the customer. The new process provides an electrical steel with the similar, same, or better magnetic properties than an electrical steel manufactured using the traditional processing that utilizes an intermediate annealing step after cold rolling and before the stamping and final annealing.

What is claimed is: 
     
         1 . A method of manufacturing an electrical steel, comprising:
 hot rolling steel into a steel sheet in one or more hot rolling passes to a post hot rolling thickness of less than 0.1 inches;   annealing the steel sheet in a first anneal after hot rolling;   cold rolling the steel sheet in one or more first cold rolling passes after the first anneal to a post first cold rolling thickness less than 0.05 inches;   annealing the steel sheet in a second anneal after the one or more first cold rolling passes;   cold rolling the steel sheet in one or more final cold rolling passes after the second annealing process to a thickness of less than 0.015 inches; and   whereby final magnetic properties are achieved in the steel sheet after the steel sheet is stamped and final annealed without an intermediate annealing process after the one or more final cold rolling passes, and before the stamping and the final annealing.   
     
     
         2 . The method of  claim 1 , wherein the composition of the electrical steel comprises:
 silicon (Si) in a range of 0.15-3.5% weight;   manganese (Mn) in a range of 0.005-1% weight;   aluminum (Al) less than or equal to 1% weight;   carbon (C) less than or equal to 0.04% weight;   antimony (Sb) or tin (Sn) less than or equal to 0.1% weight; and   wherein the remainder comprises unavoidable impurities and iron.   
     
     
         3 . The method of  claim 1 , wherein the composition of the electrical steel comprises:
 silicon (Si) is in the range of 2.8-3.5% weight;   manganese (Mn) in a range of 0.2-0.4% weight; and   aluminum (Al) in a range of 0.5-0.75% weight.   
     
     
         4 . The method of  claim 1 , further comprising:
 sending the steel sheet to a customer for the stamping and the final annealing after the stamping.   
     
     
         5 . The method of  claim 1 , wherein the first anneal comprises a batch anneal above 1600 degrees F., and the second anneal comprises a batch anneal above 1500 degrees F. 
     
     
         6 . The method of  claim 1 , wherein the final thickness of the steel sheet is 0.011 to 0.013 and the final magnetic properties comprise a permeability of greater than 7500 G/Oe and a core loss of less than 16.0 w/kg when tested at 1.0T at 400 Hz. 
     
     
         7 . The method of  claim 1 , wherein the final thickness of the steel sheet is 0.007 to 0.010 and the final magnetic properties comprise a permeability greater than 8500 G/Oe and a core loss less than 13.0 w/kg when tested at 1.0T at 400 Hz. 
     
     
         8 . A method of manufacturing an electrical steel, comprising:
 procuring a thin strip cast steel, wherein the thickness of the thin strip cast steel is less than or equal to 0.05 inches;   annealing the thin strip cast steel;   cold rolling the steel sheet in one or more cold rolling passes after annealing to a thickness of less than 0.015 inches; and   whereby final magnetic properties are achieved in the steel sheet after the steel sheet is stamped and final annealed without an intermediate annealing process after the one or more cold rolling passes, and before the stamping and the final annealing.   
     
     
         9 . The method of  claim 8 , wherein the composition of the electrical steel comprises:
 silicon (Si) in a range of 0.15-3.5% weight;   manganese (Mn) in a range of 0.005-1% weight;   aluminum (Al) less than or equal to 1% weight;   carbon (C) less than or equal to 0.04% weight;   antimony (Sb) or tin (Sn) less than or equal to 0.1% weight; and   wherein the remainder comprises unavoidable impurities and iron.   
     
     
         10 . The method of  claim 8 , wherein the composition of the electrical steel comprises:
 silicon (Si) is in the range of 2.8-3.5% weight;   manganese (Mn) in a range of 0.2-0.4% weight; and   aluminum (Al) in a range of 0.5-0.75% weight.   
     
     
         11 . The method of  claim 8 , further comprising:
 sending the steel sheet to a customer for the stamping and the final annealing after the stamping.   
     
     
         12 . The method of  claim 8 , wherein the annealing comprises a batch anneal above 1500 degrees F. 
     
     
         13 . The method of  claim 8 , wherein the thickness of the steel sheet is 0.011 to 0.013 and the final magnetic properties comprise a permeability of greater than 7500 G/Oe and a core loss of less than 16.0 w/kg when tested at 1.0T at 400 Hz. 
     
     
         14 . The method of  claim 1 , wherein the thickness of the steel sheet is 0.007 to 0.010 and the final magnetic properties comprise a permeability greater than 8500 G/Oe and a core loss less than 13.0 w/kg when tested at 1.0T @ 400 Hz. 
     
     
         15 . An electrical steel, comprising:
 silicon (Si) in a range of 0.15-3.5% weight;   wherein the remainder comprises unavoidable impurities and iron;   wherein the electrical steel is produced by
 hot rolling steel in one or more hot rolling passes into a steel sheet to a post hot rolling thickness of less than 0.1 inches; 
 annealing the steel sheet in a first anneal after hot rolling; 
 cold rolling the steel sheet in one or more first cold rolling passes after the first anneal to a thickness less than 0.05 inches; 
 annealing the steel sheet in a second anneal after the one or more first cold rolling passes; 
 cold rolling the steel sheet in one or more final cold rolling passes after the second annealing process to a thickness of less than 0.015 inches; and 
 whereby final magnetic properties are achieved in the steel sheet after the steel sheet is stamped and final annealed without an intermediate annealing process after the one or more final cold rolling passes, and before the stamping and the final annealing. 
   
     
     
         16 . The electrical steel of  claim 15 , further comprising:
 manganese (Mn) in a range of 0.005-1% weight;   aluminum (Al) less than or equal to 1% weight;   carbon (C) less than or equal to 0.04% weight; and   antimony (Sb) or tin (Sn) less than or equal to 0.1% weight.   
     
     
         17 . The electrical steel of  claim 15 , wherein the composition of the electrical steel comprises:
 silicon (Si) is in the range of 2.8-3.5% weight;   manganese (Mn) in a range of 0.2-0.4% weight; and   aluminum (Al) in a range of 0.5-0.75% weight.   
     
     
         18 . The electrical steel of  claim 15 , wherein the electrical steel is further produced by sending the steel sheet to a customer for the stamping and the final annealing after the stamping. 
     
     
         19 . The electrical steel of  claim 15 , wherein the first anneal comprises a batch anneal above 1600 degrees F., and the second anneal comprises a batch anneal above 1500 degrees F. 
     
     
         20 . The electrical steel of  claim 15 , wherein the final thickness of the steel sheet is 0.011 to 0.013 and the final magnetic properties comprise a permeability of greater than 7500 G/Oe and a core loss of less than 16.0 w/kg when tested at 400 Hz at 1.0T. 
     
     
         21 . The electrical steel of  claim 15 , wherein the final thickness of the steel sheet is 0.007 to 0.010 and the final magnetic properties comprise a permeability greater than 8500 G/Oe and a core loss less than 13.0 w/kg. 
     
     
         22 . An electrical steel, comprising:
 silicon (Si) in a range of 0.15-3.5% weight;   wherein the remainder of the composition of the electrical steel comprises unavoidable impurities and iron;   wherein the electrical steel is produced by
 procuring a thin strip cast steel, wherein the thickness of the thin strip cast steel is less than or equal to 0.05 inches; 
 annealing the thin strip cast steel; 
 cold rolling the thin strip cast steel in one or more cold rolling passes after the annealing into a steel sheet with a thickness less than 0.015 inches; and 
 whereby final magnetic properties are achieved in the steel sheet after the steel sheet is stamped and final annealed without an intermediate annealing process after the one or more cold rolling passes, and before the stamping and the final annealing. 
   
     
     
         23 . The electrical steel of  claim 22 , further comprising:
 manganese (Mn) in a range of 0.005-1% weight;   aluminum (Al) less than or equal to 1% weight;   carbon (C) less than or equal to 0.04% weight; and   antimony (Sb) or tin (Sn) less than or equal to 0.1% weight.   
     
     
         24 . The electrical steel of  claim 22 , wherein the composition of the electrical steel comprises:
 silicon (Si) is in the range of 2.8-3.5% weight;   manganese (Mn) in a range of 0.2-0.4% weight; and   aluminum (Al) in a range of 0.5-0.75% weight.   
     
     
         25 . The electrical steel of  claim 22 , wherein the electrical steel is further produced by sending the steel sheet to a customer for the stamping and the final annealing after the stamping. 
     
     
         26 . The electrical steel of  claim 22 , wherein annealing the thin strip cast steel comprises a batch anneal above 1500 degrees F. 
     
     
         27 . The electrical steel of  claim 22 , wherein the final thickness of the steel sheet is 0.011 to 0.013 and the final magnetic properties comprise a permeability of greater than 7500 G/Oe and a core loss of less than 16.0 w/kg when tested at 1.0T at 400 Hz. 
     
     
         28 . The electrical steel of  claim 22 , wherein the final thickness of the steel sheet is 0.007 to 0.010 and the final magnetic properties comprise a permeability greater than 8500 G/Oe and a core loss less than 13.0 w/kg when tested at 1.0T at 400 Hz.