Table of Contents
ISRN Chemical Engineering
Volume 2012, Article ID 103715, 6 pages
http://dx.doi.org/10.5402/2012/103715
Research Article

Theoretical and Experimental Aspects of the Corrosivity of Simulated Soil Solutions

Polytechnic Institute, Rio de Janeiro State University, Rua Bonfim 25, 28.625-570 Nova Friburgo, RJ, Brazil

Received 8 October 2012; Accepted 14 November 2012

Academic Editors: J. A. A. González and M. E. R. Shanahan

Copyright © 2012 Rodrigo Antunes de Sena et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Corrosion of buried steel pipe is a permanent engineering problem and, albeit the counter measures against degradation, when the corrosion process takes place, the damage has costly impact. In order to study the corrosion behavior of pipelines, it is possible to use actual soil extracts or simulated soil solutions. The extract is much related to specific sites and consequently too strict to permit a general understanding. The simulated soil presents, as advantage, its inorganic characteristic and easy preparation. In this paper, we present some theoretical results concerning the chemical equilibria of NS1, NS2, NS3, and NS4 simulated soil solutions. Besides, we have studied the effect of the above four media in corrosion behavior and polarization curves were performed for an API 5L X65 steel. The theoretical findings show that each ionic concentration varies for a 6–12 pH range. The experimental data suggested that the corrosion currents decrease as high is the pH and increase as high is the chloride content. Notwithstanding these facts, for multielectrolyte solutions, a simple correlation with a given ion is not straightforward but the complementary approaches used here give useful insights.