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:
Mar. 18, 2014
Filed:
Jun. 20, 2012
Masatoshi Toyoda, Nishinomiya, JP;
Keishi Matsumoto, Takarazuka, JP;
Masatoshi Toyoda, Nishinomiya, JP;
Keishi Matsumoto, Takarazuka, JP;
Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;
Abstract
A blank tube for cold drawing is used for the production of a longer-length, small-diameter tube such as a heat-transfer tube for steam generation in nuclear power facilities, wherein the blank tube will not cause scoring and chattering vibration in a drawing process. The blank tube is used to produce a cold drawn tube through cold drawing of the blank tube. The average surface roughness Ra (ANSI B46.1) of the inner surface of blank tube before drawing satisfies the condition: 0.10 μm≦Ra≦1.00 μm in the case of a blank tube for cold drawing for use in an oil-lubricated drawing. In particular, the surface roughness Ra satisfies the condition: 0.10 μm≦Ra≦0.50 μm in the case of a blank tube for use in a high-pressure lubrication drawing and made of an austenitic alloy for use in a heat-transfer tube for a steam generator.