A pinboard by
Mohsen Saeedikhani

Ph.D. Student, National University of Singapore (NUS)


Prediction of the durability of industrial protective coatings in corrosive environments

Paint is applied to protect steel structures from corrosion effectively. The long-term performance of a coating is influenced significantly by its ability to adhere to the material to which it is applied. This is not only because the coating might flake away or detach from the surface, but also because poor adhesion will allow moisture or corrosion products to undercut the coating film from areas of damage. Among the many types of paints, zinc rich paints are the prime choice for use in aggressive environments, such as offshore and industrial plants, because of their unique property of protecting the metal even when there is a degree of mechanical damage to the coating. The identification of the corrosion products that form in the damaged area is essential for a better understanding of the mechanism of corrosion protection and predicting the durability of the paint system. However, the analysis of the durability of the zinc paint system is still underrated and disregarded, unlike steels where failure analysis and life assessment methods are well established. The lack of knowledge in predicting the durability of zinc paints may be due to four reasons:

• Firstly, the mechanism of protection of substrate by zinc paints has not been well studied over the different stages of service life. • Secondly, there is a lack of information on the healing action mechanism of zinc paints within the scratches or mechanical damages. • Thirdly, the nature of the corrosion products under zinc paints have not been well characterized. • Fourthly, there is a lack of simulations or models for zinc paint failures. In order to predict the durability of zinc paints, the fastest and least expensive way is likely to be via models.

Therefore, The main scope of our research falls into three phases: First phase: Characterization of the corrosion products under zinc rich paints Second phase: Understanding the protectiveness mechanism of zinc rich paints over different stages of service life Third phase: Modelling the corrosion mechanisms of zinc rich paints