Continues Hot Dip Galvalume Line is a steel plate which is hot dip aluminum and silicon alloy .It is a steel base composite material and has excellent corrosion resistance and it is used widely in the world ,it replace galvanized strip .Aluminium strip has merits of corrosion resistance of air and oxidation resistance ,the galvanized strip has the merits of electrochemical protection .GL strip has merits of aluminium strip and galvanized strip.