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:
Jul. 16, 2024
Filed:
Jan. 22, 2019
Jfe Steel Corporation, Tokyo, JP;
Kyono Yasuda, Tokyo, JP;
Tomoyuki Yokota, Tokyo, JP;
Akihiko Tanizawa, Tokyo, JP;
Ryuji Muraoka, Tokyo, JP;
Kazukuni Hase, Tokyo, JP;
JFE Steel Corporation, Tokyo, JP;
Abstract
A method for producing a steel material for line pipes including heating a steel having a specific composition to a temperature of 1000° C. to 1200° C.; performing hot rolling such that a cumulative rolling reduction ratio in a non-recrystallization temperature range is 60% or more, a cumulative rolling reduction ratio in a temperature range of (a rolling finish temperature +20° C.) or less is 50% or more, and a rolling finish temperature is the Artransformation point or more and 790° C. or less; subsequently performing accelerated cooling from a temperature of the Artransformation point or more, at a cooling rate of 10° C./s or more, to a cooling stop temperature of 200° C. to 450° C.; and then performing reheating such that the temperature of a surface of the steel plate is 350° C. to 550° C. and the temperature of the center of the steel plate is less than 550° C.