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:
Jun. 10, 2014
Filed:
Dec. 30, 2009
Shuji Hashizume, Kanagawa, JP;
Yusuke Minami, Kanagawa, JP;
Tatsuo Ono, Kanagawa, JP;
NKKTUBES, Kanagawa, JP;
Abstract
A martensitic stainless steel for inexpensive seamless pipe having 655 MPa yield strength, high toughness and excellent corrosion resistance in high COenvironments, and a method for manufacturing thereof is provided. The steel comprises C: 0.005-0.05%, Si: 0.1-0.5%, Mn: 0.1-2.0%, P: −0.05%, S: −0.005%, Cr: 10.0-12.5%, Mo: 0.1-0.5%, Ni: 1.5-3.0%, N: −0.02%, Al: 0.01-0.1%, by weight, while FI value defined by the formula [FI=Cr+Mo−Ni−30(C+N)] being 5.00 to 8.49, and balance of substantially Fe. The method comprises the steps of reheating the cooled steel at temperatures from 780° C. to 960° C., quenching the reheated steel, and then tempering the quenched steel at temperatures from 550° C. to 650° C.