Issues about electrochemical techniques in corrosion protective performance assessment

Isabel C.P. Margarit-Mattos

Electrochemical techniques are indispensable tools for corrosion studies. Advances in electronics and fine mechanics have enabled the development of methods and instrumentation that aid knowledge generation on corrosion mechanisms. From a technological point of view, this has resulted in more efficient corrosion mitigation in all its aspects, from the development / selection of alloys, inhibitors and coatings, considering specific operating conditions. Sometimes, electrochemical techniques extend their applications beyond academia to the industrial field. The importance of dc techniques, ac techniques, their complementarities with local techniques and other physicochemical analysis for the corrosion area is undeniable.

In this context, a question that deserves reflection is the relationship that is usually made between the electrochemical behavior of materials and their “performance”. Perhaps, for some, this is just a semantic issue. However, what is often observed in the literature are conclusions about performance without considering additional corrosion tests, which are necessary even to validate the relationship between the electrochemical result and what is expected in terms of performance. These corrosion tests can be accelerated or not, standardized or not, and they need to have a duration consistent with the empirical knowledge of the current industrial practice. In our opinion, “performance” truly encompasses the electrochemical behavior of materials, but that’s not all.

The objective of this work is to support these reflections with case studies related to the performance of stainless steels, inhibitors and organic coatings.

Keywords: corrosion, electrochemistry