Method of producing grain-oriented silicon steel sheets having substantially no glass film
AssigneeKawasaki Steel Corporation
InventorsNobuyuki Morito, Toshitomo Sugiyama, Yoshio Obata
Life of this patent
Estimating the term…
Abstract
A grain-oriented silicon steel sheet having substantially no glass film can be obtained by subjecting a cold rolled silicon steel sheet having a final gauge to a decarburization annealing to form subscale on the steel sheet surface, applying an annealing separator consisting of hydrated silicate mineral fine powder, a strontium- or barium-containing compound, calcium oxide or calcium hydroxide and the remainder being Al.sub.2 O.sub.3, and finally annealing the above treated steel sheet. The steel sheet has excellent punchability when the steel sheet is coated with a phosphate system or chromate-organic resin mixture system insulating coating.
Claims4
In a method of producing grain-oriented silicon steel sheets having substantially no glass film, wherein a cold rolled silicon steel sheet having a final guage is subjected to a decarburization annealing to form subscale on the surface of the steel sheet, an annealing separator consisting mainly of Al.sub.2 O.sub.3 is applied on the subscale and then the steel sheet is subjected to a final annealing, an improvement comprising using an annealing separator consisting of 5-30% of finely particulate serpentine, 0.2-20%, calculated as strontium or barium, of compound containing strontium or barium, 2-30% of CaO or CA(OH).sub.2 and the remainder being Al.sub.2 O.sub.3.
Dependencies are inferred from the claim text.