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. 03, 1997
Filed:
Jul. 26, 1994
Jean-Louis Buret, Montbard, FR;
Denis Vuillaume, Montbard, FR;
Valinox Nucleaire, Paris, FR;
Abstract
The process relates to the aptitude for detectability of defects using eddy-currents on metal tubes cold laminated using a pilger mill and relates more particularly to the possibility of reducing the background noise and increasing the ratio between a standard signal and this background noise. The process consists of carrying out, after reduction in section by at least 30% in a cold pilger mill, a hollow drawing pass with a reduction in the external diameter of approximately 0.1% to 5%. The signal/background noise ratio can in this way be multiplied by a factor of between 2 and 3.7, in the case of a series of tubes made of INCO 690 alloy, as shown in the single figure. The invention also relates to tubes produced using this process. Application in production of steam generating tubes for nuclear power stations.