Zinc rich coatings have long been used in the protective coatings industry as one of the primary means of steel substrate protection against corrosion. The primary protection mechanism has historically been galvanic sacrificial loss of zinc metal and the simultaneous formation of protective zinc oxides and salts. Various standards and customer specifications exist to ensure that the coating will provide the necessary corrosion protection for the life of the asset. As dictated by standards and specifications, a minimum of 65 wt. % and upwards of 80 wt. % zinc is often found in the industry. As development in zinc rich coatings continue to evolves, it is imperative to consider additional methods in evaluating and understanding corrosion protection. In this paper, electrochemical tools were utilized to investigate, evaluate, and understand the corrosion protection performance.

Learning Objectives:

  1. Determine how much zinc rich coatings vary in performance.

  2. Evaluate if variation in corrosion resistance performance is correlated with the level of zinc and / or the level of galvanic activity.

  3. Understand if early open circuit potential measurements can predict corrosion performance of the zinc primer.

  4. Utilize these results to gain a better understanding of what is driving the corrosion resistance performance.

Subject
Primers, Barriers, Coating performance, Zinc rich coatings, Correlation, Cathodic protection, Zinc-rich primers, Weathering, Steel, Corrosion protection, Corrosion resistance, Zinc, Corrosion potential
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2021
Association for Materials Protection and Performance (AMPP)
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