Processing for electromagnetic silicon steel

Claim 1

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 having up to 0.07% carbon, from 0.01 to 0.25% manganese, from 0.01 to 0.09% of material from the group consisting of sulfur and selenium, from 2.5 to 4.0% silicon, up to 1.0% copper, less than 0.009% aluminum and less than 0.0006% boron; casting said steel; hot rolling said steel; cold rolling said steel; decarburizing said steel; annealing said cold roll steel of final gage; applying a refractory oxide coating to said steel; and final texture annealing said steel; the improvement comprising the steps of annealing said cold roll steel of final gage in a hydrogen-bearing atmosphere having a p H .sbsb.2 O /p H .sbsb.2 of from 0.015 to 0.3; coating the surface of said steel with a refractory oxide coating consisting essentially of: (a) 100 parts, by weight, of at least one substance from the group consisting of oxides, hydroxides, carbonates and boron compounds of magnesium, calcium, aluminum and titanium; (b) up to 100 parts, by weight, of other substances from the group consisting of boron and compounds thereof; (c) from 0.1 to 100 parts, by weight, of at least one oxide less stable than SiO 2 at temperatures up to 2150° F., said oxide being of an element other than boron; (d) up to 40 parts, by weight, of SiO 2 ; (e) up to 20 parts, by weight, of inhibiting substances; and (f) up to 100 parts, by weight, of fluxing agents; and final texture annealing said steel with said coating thereon.