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:
May. 18, 2004
Filed:
Jan. 29, 2002
Takaaki Toyooka, Aichi, JP;
Yoshikazu Kawabata, Aichi, JP;
Akira Yorifuji, Aichi, JP;
Masanori Nishimori, Aichi, JP;
Motoaki Itadani, Aichi, JP;
Takatoshi Okabe, Aichi, JP;
Masatoshi Aratani, Aichi, JP;
Yasue Koyama, Aichi, JP;
JFE Steel Corporation, , JP;
Abstract
The invention provides a high-carbon steel pipe having superior cold workability and induction hardenability, and a method of producing the steel pipe. The method comprises the steps of heating or soaking a base steel pipe having a composition containing C: 0.3 to 0.8%, Si: not more than 2%, and Mn: not more than 3%, and then carrying out reducing rolling on the base steel pipe at least in the temperature range of (Ac , transformation point −50° C.) to Ac , transformation point with an accumulated reduction in diameter of not less than 30%. A structure in which the grain size of cementite is not greater than 1.0 &mgr;m is obtained, thus resulting in improved cold workability and induction hardenability.