Accession Number : ADA192335

Title :   Determination of Tafel Constants in Nonlinear Polarization Curves.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : O'Loughlin, Thomas E

PDF Url : ADA192335

Report Date : Dec 1987

Pagination or Media Count : 140

Abstract : The presence of non-linear behavior in potentiodynamic polarization plots has resulted in difficulty in determining the Tafel constants from such plots. A FORTRAN based program involving numerical differentiation techniques was used to determine the existence of the Tafel regions. Various alloys polarized in synthetic seawater and a 3.5% NaCl solution were analyzed. Although severe concentration polarization often dominated the cathodic branches the techniques employed did allow for the selection of regions which approached linear behavior. The effects of concentration polarization in hindering the determination of Tafel constants were exemplified by the uncovering of a cathodic branch containing a small region where only activation polarization dominated followed by the onset and total domination of concentration polarization. A method of determining where the anodic and cathodic currents begin to dominate the potentiodynamic polarization curve is introduced. Keywords: Corrosion; Potentiodynamic; Theses.

Descriptors :   *ALLOYS, *NONLINEAR SYSTEMS, *POLARIZATION, ACTIVATION, BEHAVIOR, COMPUTER PROGRAMS, CORROSION, FORTRAN, LINEARITY, REGIONS, SEA WATER, SELECTION, THESES

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE