US 12,090,533 B2
Method for rolling steel sheet and method for manufacturing steel sheet
Ken Kurisu, Tokyo (JP); Kentaro Ishii, Tokyo (JP); and Kazuma Takeuchi, Tokyo (JP)
Assigned to JFE Steel Corporation, Tokyo (JP)
Appl. No. 17/425,467
Filed by JFE Steel Corporation, Tokyo (JP)
PCT Filed Dec. 26, 2019, PCT No. PCT/JP2019/051229
§ 371(c)(1), (2) Date Jul. 23, 2021,
PCT Pub. No. WO2020/158284, PCT Pub. Date Aug. 6, 2020.
Claims priority of application No. 2019-015726 (JP), filed on Jan. 31, 2019.
Prior Publication US 2022/0088653 A1, Mar. 24, 2022
Int. Cl. C21D 1/28 (2006.01); B21B 1/28 (2006.01); B21B 27/10 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); B21B 1/22 (2006.01)
CPC B21B 1/28 (2013.01) [B21B 27/10 (2013.01); C21D 8/0236 (2013.01); C21D 9/46 (2013.01); B21B 2001/221 (2013.01); B21B 2027/103 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method for rolling a steel sheet including feeding a coolant to rolls that form a rolling mill during the rolling, the method comprising:
keeping a coolant feeding rate at or lower than a predetermined rate lower than an upper constant rate at a start of operation of the rolling mill; and
increasing the coolant feeding rate to the upper constant rate when an amount of center buckles of the steel sheet reaching or exceeding an upper target value,
wherein a profile steepness of the steel sheet at a center portion is used as the amount of center buckles, the profile steepness being calculated by dividing a height difference value in a wave cycle in a sheet thickness direction at the center portion of the steel sheet by a wavelength, and
wherein the center portion is an area extending from a widthwise center line to both sides in a width direction within a range of 5% of a width of the steel sheet.