US 12,344,909 B2
Method for producing grain-oriented electrical steel sheet and cold-rolling facility
Yukihiro Shingaki, Tokyo (JP); and Yusuke Shimoyama, Tokyo (JP)
Assigned to JFE Steel Corporation, Tokyo (JP)
Filed by JFE Steel Corporation, Tokyo (JP)
Filed on Jun. 6, 2024, as Appl. No. 18/735,904.
Application 18/735,904 is a division of application No. 17/279,194, granted, now 12,037,654, previously published as PCT/JP2019/037752, filed on Sep. 26, 2019.
Claims priority of application No. 2018-183898 (JP), filed on Sep. 28, 2018.
Prior Publication US 2024/0327942 A1, Oct. 3, 2024
Int. Cl. C21D 8/12 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/48 (2006.01)
CPC C21D 8/1222 (2013.01) [C21D 8/1205 (2013.01); C21D 8/1233 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/48 (2013.01); C21D 2201/05 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A method of producing a grain-oriented electrical steel sheet comprising
reheating a steel slab comprising C: 0.01 to 0.10 mass %, Si: 2.0 to 4.5 mass %, Mn: 0.01 to 0.5 mass %, sol. Al: not less than 0.0020 mass % and less than 0.0100 mass %, N: less than 0.0080 mass %, each of S, Se, and O: less than 0.0050 mass %, and the balance being Fe and inevitable impurities to a temperature of not higher than 1300° C.,
subjecting the slab to hot rolling and then one cold rolling or more cold rollings having an intermediate annealing between each rolling to form a cold-rolled sheet with a final thickness, and
subjecting the cold-rolled sheet to a primary recrystallization annealing working also as decarburization and to a final annealing causing secondary recrystallization after applying an annealing separator on the surface of the steel sheet,
characterized in that
the final cold rolling for cold rolling the steel sheet to the final thickness is performed by using a tandem rolling mill such that at a total rolling reduction is not less than 80% and at least one of the sheet temperatures between stands thereof is within 150 to 280° C. and by extending a pass line length of the steel sheet between the stands so as to satisfy the following equation (1):

OG Complex Work Unit Math
where a distance between the stands is defined as L(m), a speed of the steel sheet passing between the stands is defined as V (mpm), and a pass time during which the steel sheet passes between the stands is defined as T(min).