Zinc is a good corrosion resistant metal because it forms a thin, protective layer of zinc oxide on its surface when it is exposed to the air. This layer provides a duller appearance but does not produce iron oxide (rust), as there is no iron in a zinc alloy. So, this layer of corrosion does not affect appears or strength as compared to other metals that “rust”.
This layer of zinc oxide helps protect the underlying metal from coming into contact with the environment, which can cause it to corrode. Zinc is also less reactive than other metals, which makes it less prone to corrosion. In fact, zinc is often used as a sacrificial anode, as used to galvanize steel, meaning that it will corrode before other metals in the same environment, protecting them from corrosion.
There are a number of ways in which zinc is used in corrosion resistant applications.
As mentioned above, zinc is also used to make galvanized steel, which is steel that has been coated with a layer of zinc. As such it is used to coat the steel used in car body parts to protect them from corrosion.
Additionally, zinc castings offer good corrosion resistance in raw form, but also, they provide a substrate for other coatings or plating for even higher corrosion resistance. So, casting can be coated with a powder coating or other decorative plating to provide a further corrosion resistant part for interior or exterior applications.
In conclusion, zinc is a good corrosion resistant metal due to its ability to form a protective layer of zinc oxide on its surface, its low reactivity, its use as a sacrificial anode, and its ability to be further coated with additional finishes. These properties make it a valuable material in a variety of industries and applications.
