Process for producing nonoriented silicon sheet steel having excellent magnetic properties in the rolling direction

Claim 1

A process for producing thin-gage substantially non-oriented silicon sheet steel but nevertheless having a slight degree of orientation to provide superior magnetic properties in the rolling direction the steps comprising: a. forming a steel slab consisting of 2.0 to 3.5% silicon, 0.30 to 0.45% aluminum, not more than 0.007% sulfur with the balance iron and usual impurities; b. heating said slab to a temperature within the range 2150° to 2250° F.; c. hot rolling said slab to hot band gage; d. pickling the hot rolled steel; e. cold rolling said steel with a two step cold reduction wherein the second cold roll effects a thickness reduction of from 50 to 60% and the steel is given an intermediate anneal between the two cold rolls at a temperature of from 1625° to 1800° F.; f. annealing the cold rolled steel at a temperature of 1450° to 1500° F. in a wet atmosphere sufficient to decarburize said steel; and g. finally annealing the decarburized steel at a temperature of from 1700° to 1900° F. in a nonoxidizing atmosphere to develop superior magnetic properties in the rolling direction; said final annealed steel, when rolled to 29-gage, characterized by an all length 15KG core loss of less than 1.50 w/lb/60 and permeability of more than 2200.