55% aluminum steel plate is a product produced by continuous hot-dip galvanizing process with cold-rolled steel coil as substrate .Galvalume (abbreviation:GL steel) is hot plating on the surface of steel plate with Al55%,Zn43.5%,Si l.5% ,the surface is smooth,has a good rsistance to atmospheric corrosion,heat resistant oxidation.Hot-dip aluzinc steel sheet is substrated on cold rolled steel(CRC)in various strength and specification Coating composition is 55％aIuminum in weight ratio．43 4％zinc．and 1 5％silicon with excellent corrosion and heat resistance performance.