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Dissimilar Metal Corrosion

Matthew Stuart, P.E., S.E., P.Eng.

Course Outline

This one hour online course discusses the process of corrosion that can occur between two dissimilar metals in the presence of a conductive solution such as moisture. It is important to have an understanding of the potential for this process so that precautions can be taken when designing and detailing connections between different metals. This course will enable the designer to avoid situations that provide the most potential for corrosion and subsequent deterioration of the connected metals. This course includes a multiple-choice quiz at the end.

Learning Objective

At the conclusion of this course, the student will:

Course Introduction

A potential difference usually exists between two dissimilar metals when they are immersed in a corrosive or conductive solution. If these two metals are placed in contact (or otherwise electrically connected) this potential difference produces electron flow between them. Corrosion of the less corrosion-resistant metal in this type of condition is usually increased and attack of the more resistant metal is decreased as compared with the behavior of the two metals when they are not in contact. Because of the electrical currents and dissimilar metals involved, this form of corrosion is called galvanic or two metal corrosion and is a form of electrochemical corrosion.

Course Content

The course content is contained in the following PDF file:

Dissimilar Metal Corrosion

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Course Summary

Corrosion can occur between dissimilar metals in the presence of a conductive solution. This process of deterioration is called galvanic corrosion. Corrosion can reduce the load carrying capacity of a component by reducing its size or cross sectional area. Engineers should be aware of the potential for this process so that proper precautions can be taken during the design and detailing of a project.

Related Links

For additional technical information related to this subject, please visit the following websites or web pages:

Prevention of Corrosion on Structural Steelwork (a PDF file)

Corrosion Doctors Site Map

NACE International - The Worldwide Corrosion Authority - NACE

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

Take a Quiz

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered professional engineer. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.