CorroZone Podcast · 16 Jun 2026
Cathodic Protection
- Free
- Lecture
- Beginner
- ~37 min
Protecting metal by polarising it cathodically: the Evans/Pourbaix basis, sacrificial-anode versus impressed-current systems, choosing anode materials, the −0.850 V vs Cu/CuSO4 criterion and its limits, over-protection risks (hydrogen embrittlement, cathodic disbondment), field applications, coating synergy, potential-survey monitoring, and stray-current interference.
Show notes
What you'll learn
- Explain the electrochemical basis of cathodic protection using Evans diagrams and Pourbaix diagrams
- Distinguish between sacrificial anode and impressed current cathodic protection systems, including their operating principles, components, advantages, and limitations
- Select appropriate anode materials (Zn, Mg, Al alloys) for different environments and explain the reasoning
- Apply the standard protection criterion for steel (−0.850 V vs Cu/CuSO4) and explain its basis and limitations
- Identify the risks of over-protection, including hydrogen embrittlement and cathodic disbondment
- Describe CP applications for buried pipelines, offshore structures, ship hulls, and reinforced concrete
- Explain how cathodic protection and protective coatings work synergistically
- Describe the fundamentals of CP monitoring including potential surveys and close interval potential surveys
- Explain stray current interference and its mitigation
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.
What you'll learn
- Explain the electrochemical basis of cathodic protection using Evans diagrams and Pourbaix diagrams
- Distinguish between sacrificial anode and impressed current cathodic protection systems, including their operating principles, components, advantages, and limitations
- Select appropriate anode materials (Zn, Mg, Al alloys) for different environments and explain the reasoning
- Apply the standard protection criterion for steel (−0.850 V vs Cu/CuSO4) and explain its basis and limitations
- Identify the risks of over-protection, including hydrogen embrittlement and cathodic disbondment
- Describe CP applications for buried pipelines, offshore structures, ship hulls, and reinforced concrete
- Explain how cathodic protection and protective coatings work synergistically
- Describe the fundamentals of CP monitoring including potential surveys and close interval potential surveys
- Explain stray current interference and its mitigation