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. 01, 2025
Filed:
Jul. 17, 2020
Nippon Steel Corporation, Tokyo, JP;
Mikiko Noguchi, Tokyo, JP;
Takashi Yamaguchi, Tokyo, JP;
NIPPON STEEL CORPORATION, Tokyo, JP;
Abstract
A method of manufacturing a martensitic stainless steel pipe includes: preparing a hollow shell, S; a pickling step, S-, in which the hollow shell is immersed in nitrohydrofluoric acid solution at a temperature below 50° C.; after pickling step S-, a high-pressure water washing step, S, in which high-pressure water is injected onto the outer surface of the hollow shell to clean the outer surface of the hollow shell; after high-pressure water washing step S, a hot-water immersion step, S, in which the hollow shell is immersed in hot water if necessary; and spraying gas onto the surface of the hollow shell, S, before a lapse of 15 minutes from completion of high-pressure water washing step Sor hot-water immersion step S