How To Explain Corrosion

Introduction to Corrosion Science

This textbook is intended for a one-semester course in corrosion science at the graduate or advanced undergraduate level. The approach is that of a physical chemist or materials scientist, and the text is geared toward students of chemistry, materials science, and engineering. This textbook should also be useful to practicing corrosion engineers or materials engineers who wish to enhance their understanding of the fundamental principles of corrosion science. It is assumed that the student or reader does not have a background in electrochemistry. However, the student or reader should have taken at least an undergraduate course in materials science or physical chemistry. More material is presented in the textbook than can be covered in a one-semester course, so the book is intended for both the classroom and as a source book for further use. This book grew out of classroom lectures which the author presented between 1982 and the present while a professorial lecturer at George Washington University, Washington, DC, where he organized and taught a graduate course on “Environmental Effects on Materials.” Additional material has been provided by over 30 years of experience in corrosion research, largely at the Naval Research Laboratory, Washington, DC and also at the Bethlehem Steel Company, Bethlehem, PA and as a Robert A. Welch Postdoctoral Fellow at the University of Texas. The text emphasizes basic principles of corrosion science which underpin extensions to practice.

Passivity and Localized Corrosion

Corrosion Control

Human beings undoubtedly became aware of corrosion just after they made their first metals. These people probably began to control corrosion very so on after that by trying to keep metal away from corrosive environments. "Bring your tools in out of the rain" and "Clean the blood off your sword right after battle" would have been early maxims. Now that the mechanisms of corrosion are better understood, more techniques have been developed to control it. My corrosion experience extends over 10 years in industry and research and over 20 years teaching corrosion courses to university engineering students and industrial consulting. During that time I have developed an approach to corrosion that has successfully trained over 1500 engineers. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgicalor environmental cells, and (3) corrosive-mechanical interactions. It seems more logical to group corrosion according to mechanisms than to arbitrarily separate them into 8 or 20 different types of corrosion as if they were unrelated. University students and industry personnel alike generally are afraid of chemistry and consequently approach corrosion theory very hesitantly. In this text the electrochemical reactions responsible for corrosion are summed up in only five simple half-cell reactions. When these are combined on a polarization diagram, which is explained in detail, the electrochemical pro cesses become obvious.