What is the term for the protective coating applied to prevent corrosion on sheet metal?

The protective coating applied to prevent corrosion on sheet metal is often referred to as anodizing. This process involves converting the metal surface into a durable, corrosion-resistant oxide layer through an electrochemical process. Anodizing not only enhances the metal's resistance to corrosion but also improves its surface hardness and can provide aesthetic enhancements through various colors.

Anodizing is commonly used for aluminum, creating a thick, protective layer that is integral to the material. This type of coating is highly effective because it adheres strongly to the substrate and provides excellent durability against environmental factors that could lead to corrosion.

While galvanization, electroplating, and powder coating are also methods used for corrosion protection, they operate differently and are applied in different contexts. Galvanization involves coating steel or iron with a layer of zinc to prevent rusting, electroplating uses a thin layer of metal to provide a protective or decorative finish, and powder coating involves applying a dry powder paint that is then cured under heat. However, in the context of sheet metal specifically referring to aluminum, anodizing is the most relevant and effective method for creating a protective layer against corrosion.