Boron and copper bearing silicon steel and processing therefore

In a process for producing electromagnetic silicon steel having a cube-on-edge orientation, which process includes the steps of:

• preparing a melt of silicon steel containing from 0.02 to 0.06% carbon, from 0.015 to 0.15% manganese, from 0.01 to 0.05% of material from the group consisting of sulfur and selenium, from 0.0006 to 0.0080% boron, up to 0.0100% nitrogen, no more than 0.008% aluminum and from 2.5 to 4.0% silicon;
• casting said steel;
• hot rolling said steel to an intermediate thickness of from about 0.050 to about 0.120 inch;
• cold rolling said steel from said intermediate thickness to a final gage no greater than 0.020 inch without an intermediate anneal between cold rolling passes;
• preparing several coils from said steel;
• decarburizing said steel;
• and final texture annealing said steel;
• the improvement comprising the step of incorporating between 0.3 and 1.0% copper in said melt, said copper improving the magnetic quality of said steel so that at least 25% of said coils have a permeability of at least 1870 (G/O.sub.e) at 10 oersteds and a core loss of no more than 0.700 watts per pound at 17 kilogauss, at both ends, said melt consisting essentially of, by weight, from 0.02 to 0.06% carbon, from 0.015 to 0.15% manganese, from 0.01 to 0.05% of material from the group consisting of sulfur and selenium, from 0.0006 to 0.0080% boron, up to 0.0100% nitrogen, no more than 0.008% aluminum, from 2.5 to 4.0% silicon, between 0.3 and 1.0% copper, balance iron.