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:
Dec. 01, 1992
Filed:
Jul. 22, 1991
Yusuke Minami, Kawasaki, JP;
Shuji Hashizume, Kawasaki, JP;
Tatsuo Takaoka, Kawasaki, JP;
Takemi Yamada, Kawasaki, JP;
NKK Corporation, Tokyo, JP;
Abstract
A martensitic stainless steel having good corrosion resistance suitable for use in an oil well having 0.08 to 0.25 wt. % C, 14 to 16 wt. % Cr, 1.0 wt. % or less Si, 2.0 wt. % or less Mn, 0.5 to 3.0 wt. % Ni, 0.03 to 0.10 wt. % N, 0.04 wt. % or less P, 0.01 wt. % or less S, 0.1 to 1.0 wt. % Mo, the balance being Fe and inevitable impurities. The Cr, C, Ni and N being in amounts such that 20 wt. % .gtoreq.Cr-12C+0.75 Ni+10N.gtoreq.13 wt. %. The martensitic stainless steel having a content of .delta.-ferrite of 10% or less. The martensitic stainless steel can contain at least one of 0.05 to 0.30 wt. % V and 0.01 to 0.1 wt. % Nb. Also the martensitic stainless steel can contain 0.5 to 3.0 wt. % Cu. Further the martensitic stainless steel can contain 0.5 to 3.0 wt. % Cu, and at least one of 0.05 to 3.0 wt. % V and 0.01 to 0.1 wt. % Nb.