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:
Dec. 30, 2008
Filed:
Aug. 22, 2007
Kouji Nakaike, Wakayama, JP;
Yasuyoshi Hidaka, Kobe, JP;
Sumio Iida, Takarazuka, JP;
Hiroki Kusuda, Osaka, JP;
Masami Sakiyama, Wakayama, JP;
Kouji Nakaike, Wakayama, JP;
Yasuyoshi Hidaka, Kobe, JP;
Sumio Iida, Takarazuka, JP;
Hiroki Kusuda, Osaka, JP;
Masami Sakiyama, Wakayama, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A seamless tube is manufactured while effectively suppressing the occurrence of carburization in the seamless tube without interfering with operations. A seamless tube is manufactured by a step of washing at least a portion of a conveyor installed in a conveying step of a mandrel bar B which is situated from a lubricant applying deviceto the entrance of a mandrel mill, a step of washing, on the upstream side of the lubricant applying device, a mandrel bar B which was used for elongation rolling, and a step of applying a non-graphite-based lubricant to the mandrel bar B with the lubricant applying device, wherein the conveyor and the mandrel bar B are each washed such that the amount of graphite C2 (g/m) adhering to the surface of the mandrel bar B before it is provided to elongation rolling and the amount of carbon C1 (g/m) contained in the organic binder of the applied lubricant satisfy Equation 1: 0.08×C1+0.05×C2≦3 and Equation 2: 3≦C1+C2≦50.