Determination of electrode potentials on local metals surfaces and welded joints

Abstract

A method and installation for measuring electrode potentials on the local areas of metal surfaces and welded joints are developed. The special of the method and design of the installation is the supply of electrolyte to the metal surface due to the capillary effect of the wick made of fiber material. A gold wire was chosen as a reference electrode. Combination of the capillary supply of the electrolyte and electrode of small diameter provides measuring of the electrode potentials on rather small (up to structural components) surface areas. Change in the electrode position and electrode potential recorded in continuos mode can be visualized and scaled-up on a computer display. The developed procedure provides determination of the electrode potentials on the surfaces of metal materials with electrochemical heterogeneity and can be used to assess the corrosion resistance of materials; electrochemical heterogeneity of the structural components; forecast the service life of the metal structures; simulate the technologies of welding and soldering steel with metal corrosion coatings with a minimal damage to the protective coating and determine the corrosion properties of the products in service to predict their residual life.