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:
Feb. 18, 2025
Filed:
Mar. 19, 2020
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE Steel Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/08 (2006.01); B05D 7/14 (2006.01); C21D 6/00 (2006.01); C21D 8/10 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/24 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/58 (2006.01);
U.S. Cl.
CPC ...
C21D 9/085 (2013.01); B05D 7/146 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 8/105 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/24 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/58 (2013.01);
Abstract
A steel material for line pipes has a specific composition. The metallic microstructure of the steel material at a ⅛-plate thickness position below the surface includes bainite of an area fraction of 85% or more, polygonal ferrite of an area fraction of 10% or less, and martensite-austenite constituent of an area fraction of 5% or less. The 0.23% compressive strength of a portion of the steel material which extends from the surface to the ⅛-plate thickness position in a transverse direction is 340 MPa or more. The temperature at which a percent ductile fracture of the steel material measured in a DWTT test becomes 85% or more is −10° C. or less.