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:
Oct. 07, 2014
Filed:
Jan. 31, 2011
Kunio Kondo, Hyogo, JP;
Yuji Arai, Hyogo, JP;
Kunio Kondo, Hyogo, JP;
Yuji Arai, Hyogo, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
A steel pipe with excellent expandability, comprising, by mass %, C: 0.1 to 0.45%, Si: 0.3 to 3.5%, Mn: 0.5 to 5%, P: less than or equal to 0.03%, S: less than or equal to 0.01%, soluble Al: 0.01 to 0.8% (more than or equal to 0.1% in case Si content is less than 1.5%), N: less than or equal to 0.05%, O: less than or equal to 0.01%, and balance being Fe and impurities, having a mixed microstructure comprising ferrite and one or more selected from fine pearlite, bainite and martensite, and having a tensile strength of more than or equal to 600 MPa and a uniform elongation satisfying following formula (1). This steel pipe, having the above described chemical composition, can be obtained, for example, by being heated at temperatures from 700 to 790° C., then being forced-cooled down to a temperature of lower than or equal to 100° C. with the cooling rate of greater than or equal to 100° C./min at the temperature from 700 to 500° C.u-el≧28−0.0075TS  (1),