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:
Feb. 26, 1980
Filed:
Oct. 10, 1978
Ken-ichi Kanno, Yokohama, JP;
Masayuki Suzuki, Yokohama, JP;
Yuichi Sato, Atsugi, JP;
Masamichi Machida, Fuchu, JP;
Tokyo Shibaura Denki Kabushiki Kaisha, Kawasaki, JP;
Abstract
A metal test piece is disposed in a cell filled with a test solution. The metal test piece is electrically charged instantaneously through a counter electrode so as to have a few millivolts polarization potential .eta..sub.t. The charge consumed by the corrosion reaction of the test piece is measured by a potential recorder in the form of a variation of the polarization potential .eta..sub.t with respect to time t. The measured (.eta..sub.t -t) relation is analyzed to obtain a polarization resistance R.sub.P of the metal test piece. After the potential of the metal test piece returns to its natural potential Ecorr, the test piece is charged again until its polarization potential .eta..sub.t rises to 50 millivolts or more, and the (.eta..sub.t -t) relation is measured in the same way as mentioned above. Based on this relation, the Tafel slope .beta..sub.a of the anodic reaction is obtained. After the potential of the metal test piece has returned to its natural potential Ecorr, the test piece is so charged for the third time as to have its polarization potential .eta..sub.t lowered to -50 millivolts or less, and the (.eta..sub.t -t) relation is measured. This relation is analyzed to obtain the Tafel slope .beta..sub.c of the cathodic reaction. Based on the polarization resistance R.sub.P, Tafel slopes .beta..sub.a and .beta..sub.c, the corrosion current density I.sub.corr is obtained, from which the corrosion rate V is calculated.