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. 04, 2019
Filed:
Mar. 20, 2015
Applicant:
Jfe Steel Corporation, Tokyo, JP;
Inventors:
Assignee:
JFE Steel Corporation, , JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D 9/14 (2006.01); C21D 7/02 (2006.01); C21D 1/18 (2006.01); C21D 1/25 (2006.01); C21D 1/28 (2006.01); C21D 9/08 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/32 (2006.01); C22C 38/38 (2006.01); F02M 61/16 (2006.01); C21D 8/10 (2006.01); C22C 38/00 (2006.01); C22C 38/58 (2006.01); F02M 55/02 (2006.01);
U.S. Cl.
CPC ...
C21D 9/14 (2013.01); C21D 1/18 (2013.01); C21D 1/25 (2013.01); C21D 1/28 (2013.01); C21D 7/02 (2013.01); C21D 8/10 (2013.01); C21D 8/105 (2013.01); C22C 38/00 (2013.01); C22C 38/06 (2013.01); C22C 38/58 (2013.01); F02M 55/02 (2013.01); F02M 61/166 (2013.01); C21D 9/08 (2013.01); C21D 2211/001 (2013.01); F02M 2200/9053 (2013.01);
Abstract
A seamless steel tube has a particular composition and a structure with an average prior γ grain size of 150 μm or less in an axial cross-section after cold drawing and heat treatment. The structure retards the growth of a fatigue crack. The steel tube has a tensile strength TS of 500 MPa or more and good internal pressure fatigue resistance and is suitable for use as a fuel injection tube under high injection pressures. The composition of the steel tube may further contain at least one of Cu, Ni, Cr, Mo, and B; at least one of Ti, Nb, and V; and/or Ca.