API 571 Certification (Corrosion & Materials) Practice Test

What is the most effective way to mitigate metal dusting?

1. Using copper alloys

2. Using aluminized coatings

3. Using pure nickel

4. Using low alloy steel

The correct answer is: Using aluminized coatings

Using aluminized coatings is the most effective way to mitigate metal dusting because these coatings provide a protective barrier that enhances the resistance of underlying materials to both oxidative and corrosive environments. Metal dusting typically occurs in high-temperature carbon-rich environments, causing the deterioration of metals, especially iron and nickel-based alloys. By applying aluminized coatings, aluminum forms a protective oxide layer when exposed to these harsh conditions, effectively preventing metal loss and minimizing metal dusting. Aluminized coatings help in creating a surface that slows down the diffusion of carbon into the substrate material, therefore reducing the formation of carbon-rich phases that contribute to dusting. These coatings are particularly beneficial in high-temperature applications, which are common in petrochemical processing, where metal dusting is often a concern. The other choices represent materials that may not provide the necessary protection against metal dusting. For example, copper alloys can be susceptible to corrosion and might not perform well in reducing metal dusting under the specific conditions where it typically occurs. Pure nickel, although it has some resistance to certain forms of corrosion, may still be vulnerable to metal dusting when exposed to carbon-rich environments. Low alloy steel, while used in various applications, does not provide the specific protective benefits required to effectively combat metal dust