公开(公告)号：US20210040579A1

公开(公告)日：2021-02-11

申请号：US16976898

申请日：2019-02-06

Applicant: JFE STEEL CORPORATION

Inventor： Ken SAKAI ,  Shinichi KITAMURA ,  Kohei KURIHARA ,  Yusuke OTA

IPC: C21D9/56 ,  C21D1/26

Abstract: A method of annealing a steel sheet in an annealing furnace, including: supporting and conveying a steel sheet with hearth rolls; and supporting and conveying the steel sheet with a full-ceramic hearth roll as a hearth roll located in an area where a furnace temperature is equal to or higher than 950° C., wherein a main constituent of the full-ceramic hearth roll is silicon nitride with use of an Al—Y-based sintering aid.

公开(公告)号：US20240102125A1

公开(公告)日：2024-03-28

申请号：US18275243

申请日：2021-12-27

Applicant: JFE STEEL CORPORATION

Inventor： Masaki HIRAI ,  Yusuke OTA ,  Ichiro TANOKUCHI

IPC: C21D11/00 ,  C21D9/573

CPC classification number: C21D11/005 ,  C21D9/573

Abstract: A cooling water temperature control method, includes: calculating thickness of a water film remaining on a steel sheet; calculating a change in the thickness of the water film; calculating a change in temperature of the steel sheet; calculating a steel sheet temperature on an exit side of a draining roll at which a position where the thickness of the water film on the steel sheet becomes zero coincides with an exit side position of a drying equipment, and setting the calculated temperature to a lower limit value; calculating a steel sheet temperature on the exit side of the draining roll at which the steel sheet temperature on the entrance side of coating equipment coincides with a predetermined temperature and setting the calculated temperature to an upper limit value; and controlling the temperature of cooling water within a range of the lower limit value and the upper limit value.