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:
Apr. 03, 2001
Filed:
Feb. 19, 1999
Applicant:
Inventors:
Assignee:
Sumitomo Metal Industries, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B32B 9/00 ; B32B 1/504 ;
U.S. Cl.
CPC ...
B32B 9/00 ; B32B 1/504 ;
Abstract
The martensitic stainless steel product comprises a base steel and a dual oxide scale layer on a surface of the steel, wherein the dual scale layer includes an inner scale layer containing FeCr,O,and Fe,O,as main components and an outer scale layer containing Fe,O,as a main component and having an outermost Fe,O,layer; or includes an inner scale layer containing FeCr,O,and FeO as main components and an outer scale layer containing FeO and Fe,O,as main components and having an outermost Fe,O,layer. If the product is a steel pipe, it exhibits excellent corrosion resistance when used for an oil country tubular goods or line pipe.