Process for producing nonoriented silicon sheet steel having excellent magnetic properties in the rolling direction
AssigneeUnited States Steel Corporation
InventorEdward B. Stanley
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Abstract
A process for producing a fully processed nonoriented silicon sheet steel having excellent magnetic properties in the rolling direction wherein a steel containing 2.0 to 3.5% silicon and 0.30 to 0.45% aluminum is hot rolled to hot band gage, pickled, and cold rolled with a two-step cold roll with an intermediate anneal such that the second cold roll effects a thickness reduction to 50 to 60%. The cold rolled steel is then decarburized annealed and final annealed according to conventional practices.
Claims1
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.degree. to 2250.degree. 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.degree. to 1800.degree. F.;
- f. annealing the cold rolled steel at a temperature of 1450.degree. to 1500.degree. F. in a wet atmosphere sufficient to decarburize said steel;
- and
- g. finally annealing the decarburized steel at a temperature of from 1700.degree. to 1900.degree. 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.
Dependencies are inferred from the claim text.