Galvalume coil (also known as galvalume steel sheet, common grades such as AZ150, AZ185, etc.) is a metal material with aluminum-zinc alloy (usually composed of 55% aluminum, 43.4% zinc, 1.6% silicon) plated on the surface of steel sheet, which has both the corrosion resistance of aluminum and the cathodic protection of zinc. It has a wide range of applications, especially in harsh environments.