The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 28, 2023
Filed:
Nov. 22, 2022
Posco Co., Ltd, Pohang-si, KR;
Yeon-Sang Ahn, Gwangyang-si, KR;
Chang-Hyo Seo, Gwangyang-si, KR;
Kang-Hyun Choi, Gwangyang-si, KR;
Eul-Yong Choi, Gwangyang-si, KR;
POSCO CO., LTD, Pohang-si, KR;
Abstract
Provided is a method of manufacturing a high strength steel sheet having excellent workability, including: reheating a steel slab; hot-rolling the reheated steel slab at an Ar3 transformation point or higher; coiling in a temperature range of 400 to 700° C.; primary cooling at a cooling rate of 0.1° C./s or less to room temperature; producing a cold rolled steel sheet at a cold reduction ratio of 40 to 70%; continuously annealing the cold rolled steel sheet in a temperature range of Ac1+30° C. to Ac3−20° C.; secondary cooling at a cooling rate of 10° C./s or less to 630 to 670° C.; third cooling to 400 to 500° C. at a cooling rate of 5° C./s or more in a hydrogen; maintaining for 70 seconds or more; hot-dip galvanizing; and performing a final cooling to Ms or less at a cooling rate of 1° C./s or more.