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Introduction to Cathodic Protection

Study the significance of cathodic protection in the prevention and control of corrosion in this free online course.

Publisher: NPTEL
Gain an understanding of the significance of cathodic protection in the prevention and control of corrosion of engineering structures in this free online course. Engineering structures like pipelines and storage tanks are among the major infrastructures across the globe which are impacted by widespread corrosion. By completing this course, you will learn a lot about corrosion and study how to control or prevent it by means of cathodic protection.
Introduction to Cathodic Protection
  • Duration

    3-4 Hours
  • Students

  • Accreditation






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Buried engineering structures such as pipelines, storage tanks, offshore structures, etc. which are very important for any nation are one of the major infrastructures across the globe that are suffering corrosion extensively, cathodic protection is the best way to prevent such corrosion. This free online course will examine the importance of these buried engineering structures and explain why there is a need to be concerned about them. You will be introduced to the concept of corrosion which is relevant to pipelines, storage tanks, and offshore structures. The various forms of corrosion that these structures are affected by, will be briefly discussed. The composition or functional materials required for corrosion to occur, the electrochemical nature of corrosion, as well as control measures, regarding corrosion, will also be explained. You will then consider the factors affecting the life or performance of buried structures. Pipeline corrosion is unique because it faces two kinds of corrosion. These two kinds of corrosion, as well as the role of soil, microbes, and metal surfaces on corrosion, will be examined.

Cathodic protection is very important for a range of structures, so there is a need to understand how cathodic protection engineering can be implemented. The corrosion of buried structures cannot be completely avoided; therefore, various criteria have been developed to ensure adequate protection of these structures. Each criterion has its merits and limitations but understanding the basics of the fundamentals of cathodic protection is very important. You will study the various types of criteria available for cathodic protection, as well as their advantages, and disadvantages. Additionally, you will learn the electrochemical principles as applicable to cathodic protection engineering. Three important principles will be covered in this section, the basic principle of cathodic protection, the use of the Evans diagram, and the types of cathodic protection one may apply to engineer structures. Then, the differences between chemical and electrochemical reactions in corrosion will be highlighted. The Evans diagram and its relationship with cathodic protection will be discussed. It will also be used to check the governing relationship between potential and current in the electrochemical corrosion process of metals.

Moreover, the pipelines concerning engineering structures in a typical plant and buried structures undergo unknown physical and climate changes over time. In the final section of the course, you will learn the concepts involved in assessing pipelines experiencing corrosion through surveys. This will be taught in two parts. The first part consists of natural surveys that apply to buried pipelines, the soil resistivity survey, and the pipe-to-soil potentials survey. The second part will deal with the line current and the drain current measurements surveys. You will also be shown the list of information that is required to survey a pipeline with or without cathodic protection. Also, you will study how to identify and control hot spots in a pipeline experiencing severe corrosion as well as determine the quality of protective coatings in buried pipelines. Lastly, the anode ground bed in the cathodic protection of buried structures will be discussed. You will be introduced to backfill and its role in cathodic protection and consider why it may be necessary to be concerned about anode ground bed. The deep-well and remote ground bed anodes will also be highlighted. This course will be of interest to researchers, engineers, or anyone involved with and interested in the study of the corrosion of buried engineering structures. So do not delay, start learning today!

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