Galvanic Corrosion

What you'll learn

• Explain the electrochemical mechanism of galvanic corrosion including the roles of potential difference, electron flow, and ionic current
• Distinguish the galvanic series from the standard electrochemical series and explain why the two can differ substantially for real alloys
• Identify which metal in a galvanic couple will act as the anode and which as the cathode using the galvanic series
• Explain the critical importance of the cathode-to-anode area ratio and predict whether a given configuration is dangerous or acceptable
• Describe how electrolyte conductivity, distance, pH, temperature, and dissolved oxygen affect galvanic corrosion severity
• Use an Evans diagram to determine the galvanic potential and corrosion current for a dissimilar-metal couple
• Predict qualitatively how changes in cathode area, oxygen concentration, or inhibitor addition shift Evans diagram intersections
• Apply mitigation strategies including materials selection, electrical insulation, cathode coating, cathodic protection, and design optimisation
• Identify appropriate mitigation approaches for galvanic corrosion in marine, aerospace, pipeline, and plumbing contexts

Who this is for

Anyone beginning their study of corrosion — students, engineers, and technical staff who want a solid foundation in why metals corrode and what can be done about it. No prior background assumed.