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. 12, 2025
Filed:
Apr. 23, 2020
Nippon Steel Corporation, Tokyo, JP;
Kosei Kato, Tokyo, JP;
Yusaku Tomio, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
The duplex stainless seamless steel pipe according to the present disclosure has the chemical composition described in the description and a microstructure composed of 30.0 to 70.0% of ferrite, and austenite. In an observation field of view region of a square shape with a side of 1.0 mm, the region including a center portion of wall thickness and including an L direction and a T direction. A number of intersections NT, which is the number of intersections between the line segments Tto Twhich is four line segments extending in the T direction and a ferrite interface, is 40.0 or more. A number of intersections NL, which is the number of intersections between the line segments Lto Lwhich is four line segments extending in the L direction and the ferrite interface, and the number of intersections NT satisfy Formula (1).≥2.0 (1)