What element is used as a coating on galvanized pipe?

What element is used as a coating on galvanized pipe?

• A. Zinc
• B. Iron
• C. Copper
• D. Nickel

Answer: (A)

Zinc is used as the coating on galvanized pipe. The process, called galvanizing, applies a protective zinc layer to steel or iron to prevent rust and corrosion. Zinc protects by two main effects: it acts as a barrier to moisture and oxygen, and it provides sacrificial protection because zinc is more reactive than iron. If the coating gets damaged, the exposed steel is still protected because zinc will preferentially corrode, forming a stable patina over time that further slows corrosion. The hot-dip method often creates zinc-iron alloy layers that help the coating adhere strongly to the metal. Iron is the base metal being protected, not the coating. Copper and nickel coatings exist in other applications, but they are not the standard coating used for galvanized pipe.

Zinc is used as the coating on galvanized pipe. The process, called galvanizing, applies a protective zinc layer to steel or iron to prevent rust and corrosion. Zinc protects by two main effects: it acts as a barrier to moisture and oxygen, and it provides sacrificial protection because zinc is more reactive than iron. If the coating gets damaged, the exposed steel is still protected because zinc will preferentially corrode, forming a stable patina over time that further slows corrosion. The hot-dip method often creates zinc-iron alloy layers that help the coating adhere strongly to the metal.

Iron is the base metal being protected, not the coating. Copper and nickel coatings exist in other applications, but they are not the standard coating used for galvanized pipe.