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:
Aug. 02, 2022
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;
Abstract
A method for producing a steel material for line pipes which has a tensile strength of 570 MPa or more, a compressive strength of 440 MPa or more, and a thickness of 30 mm or more, the method 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; and subsequently performing accelerated cooling from a cooling start temperature of the Artransformation point or more, at a cooling rate of 10° C./s or more, until the temperature of a surface of a steel plate reaches 300° C. to 500° C.