Title:
PRODUCTION OF NONORIENTED SILICON STEEL SHEET WITH HIGH MAGNETIC FLUX DENSITY AND LOW IRON LOSS
Document Type and Number:
Japanese Patent JP3399726
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To produce a nonoriented silicon steel sheet with high magnetic flux density and low iron loss by coarsening the crystalline grains of a steel, having a specific composition consisting of C, Si, Mn, Al, P, S, N, and Fe, by means of the control of coiling after hot rolling and the application of hot rolled plate annealing.
SOLUTION: A steel, having a composition consisting of, by weight, ≤0.010% C, 0.1-4.0% Si, ≤1.5% Mn, ≤1.5% Al, ≤0.1% P, ≤0.01% S, ≤0.01% N, and the balance Fe with inevitable impurities, is hot-rolled and then subjected to hot rolled plate annealing or to self-annealing. The resultant plate is cold-rolled once or is cold-rolled two or more times, subjected to intermediate annealing between cold rolled stages, to final sheet thickness, followed by finish annealing. At this time, the temp. at coiling after hot rolling, the outside diameter of coil, and the thickness of plate are regulated to ≤800°C, ≤2700mm, and ≥1.2mm, respectively, and hot rolled plate annealing is performed at a temp. not lower than the recrystallization temp. for ≤5min, or, coiling temp. is regulated to ≤1000°C and self-annealing is done for ≤5hr. By this procedure, grain size before cold rolling is coarsened to ≥50μm. Further, rolling rate at cold rolling is limited to 70-90%.
Inventors:
Tomoyuki Abe
Tomoji Kumano
Kazufumi Hanzawa
Shinichi Kaneo
Tomoji Kumano
Kazufumi Hanzawa
Shinichi Kaneo
Application Number:
JP28872495A
Publication Date:
April 21, 2003
Filing Date:
November 07, 1995
Export Citation:
Assignee:
Nippon Steel Corporation
International Classes:
C21D8/12; C22C38/00; C22C38/06; H01F1/16; (IPC1-7): C21D8/12; C22C38/00; C22C38/06; H01F1/16
Domestic Patent References:
| JP892643A |
Attorney, Agent or Firm:
Tachio Chanogi (1 outside)