Processing for high permeability silicon steel comprising copper

Claim 1

IN A PROCESS FOR PRODUCING ELECTROMAGNETIC SILICON STEEL HAVING A CUBE-ON-EDGE ORIENTATION AND A PERMEABILITY OF AT LEAST 1850 (G/OE) AT 10 OERSTEDS, WHICH PROCESS INCLUDES THE STEPS OF: ROLLING SAID STEEL INTO A HOT ROLLED BAND; SUBJECTING SAID STEEL TO AT LEAST ONE COLD ROLLING; SUBJECTING SAID STEEL TO A FINAL ANNEALING PRIOR TO THE FINAL COLD ROLLING; DECARBURIZING SAID STEEL; AND FINAL TEXTURE ANNEALING SAID STEEL; THE IMPROVEMENT COMPRISING THE STEPS OF CARRYING OUT SAID FINAL ANNEAL PRIOR TO THE FINAL COLD ROLLING AT A TEMPERATURE OF FROM 1400* TO 2150*F FOR A PERIOD OF FROM 15 SECONDS TO 2 HOURS; COOLING SAID STEEL FROM A TEMPERATURE BELOW 1700*F AND ABOVE 750*F TO A TEMPERATURE AT LEAST AS LOW AS 500*F WITH A LIQUID QUENCHING MEDIUM OR GASEOUS STREAM AND FROM ITS MAXIMUM ANNEALING TEMPERATURE TO SAID TEMPERATURE BELOW 1700*F AND ABOVE 750*F AT A RATE WHICH IS NO FASTER THAN ONE WHEREIN THE STEEL IS COOLED IN A STATIC ATMOSPHERE OR IN A CONTINUOUS PROCESSING LINE WHERE THERE IS SOME RELATIVE MOTION BETWEEN THE ATMOS SPHERE AND THE STEEL, ALTHOUGH THE ONLY DELIBERATE MOTION IS THAT IMPARTED TO THE STEEL; AND COLD ROLLING THE COOLED STEEL AT A REDUCTION OF AT LEAST 80 PERCENT; SAID MELT CONSISTING ESSENTIALLY OF, BY WEIGHT, UP TO 0.70% CARBON FROM 2.60 TO 4.0% SILICON, FROM 0.03 TO 0.24% MANGANESE, FROM 0.01 TO 0.07% SULFUR, FROM 0.015 TO 0.04% ALUMINUM, UP TO 0.02% NITROGEN, FROM 0.1 TO 0.5% AND THE BALANCE IRON.