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US 4,775,430 AGranted
Process for producing grain-oriented electrical steel sheet having improved magnetic properties
AssigneeNippon Steel Corporation
InventorsOsamu Tanaka, Hiroshi Sato
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Abstract
For improving the properties of a glass film on a grain-oriented electrical steel sheet, the annealing separator applied on a decarburized steel sheet is prepared by: calcining at a high temperature to reduce the activity thereof; hydrating only on the outermost layer of MgO particles; and adding a Ti, B, or S compound to MgO.
Claims7
A process for producing a grain-oriented electrical steel sheet having a uniform glass film and improved magnetic properties, comprising steps of:
- hot rolling a silicon steel slab to form a hot-rolled strip;
- annealing the hot-rolled strip;
- cold-rolling the hot-rolled strip once or twice with an intermediate annealing therebetween;
- decarburization-annealing the cold-rolled strip;
- applying an annealing separator on the cold-rolled strip, and finishing annealing, characterized by, after decarburization-annealing, applying an annealing separator comprising MgO, which is prepared by calcining an Mg compound at a high temperature to reduce the activity thereof and then forming on an outermost surface of particles thereof a hydrate layer at an amount of from 0.3 to 2.0% by weight per MgO after calcining, and one or more of 0.5 to 15 parts by weight of a Ti compound in terms of Ti based on 100 parts by weight of MgO, 0.03 to 0.15 parts by weight of a B compound in terms of B based on 100 parts by weight of MgO, 0.03 to 1.0 parts by weight of a S compound in terms of S based on 100 parts by weight of MgO, followed by finishing annealing.
2 more elements
Dependencies are inferred from the claim text.