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. 05, 2014
Filed:
Dec. 29, 2009
Shoichiro Usui, Numazu, JP;
Katsunori Nagao, Wakayama, JP;
Shoichiro Usui, Numazu, JP;
Katsunori Nagao, Wakayama, JP;
Usui Kokusai Sangyo Kaisha, Shizudoka, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
There is provided a steel pipe for fuel injection pipe that assures prolonged fatigue life and high reliability by securing a high critical internal pressure, at which fatigue fracture does not occur, while the material strength is high. A steel pipe for fuel injection pipe consisting of, by mass percent, C: 0.12 to 0.27%, Si: 0.05 to 0.40%, and Mn: 0.8 to 2.0%, the balance being Fe and impurities, the impurities containing Ca: 0.001% or less, P: 0.02% or less, and S: 0.01% or less, wherein the tensile strength thereof is not lower than 900 N/mm, and the maximum diameter of a nonmetallic inclusion present during at least 20 μm depth from the inner surface of the steel pipe is not larger than 20 μm. Further, this steel pipe can contain one or more kinds of Cr: 1% or less, Mo: 1% or less, Ti: 0.04% or less, Nb: 0.04% or less, and V: 0.1% or less.