prime hot dipped galvanized steel coil for roofing material

1)Aluminum and zinc galvanized steel is the best combination of

     components and structure of the alloy coated steel.

2)Alloying elements aluminum, zinc and silicon-containing coating.
3)It combines aluminum corrosion resistance, heat resistance and

     zinc electrochemical (sacrificial anode) Performance

                                     Good corrosion resistance

1)Under various environmental conditions, Galvalume exhibit excellent corrosion resistance

     than galvanized steel sheet of the same thickness,and its service life is 2-6 times

     that of ordinary galvanized steel.Galvanized parts due to the deformation of

     micro-cracks less than galvanizing, thus forming region is much higher than the

     corrosion resistance hot dip galvanized.

2)There are examples of the use of the roof for 20 years in North America.
3)It sort of life: rural industrial atmosphere --- --- --- general atmosphere of severe marine

     sub-marine atmosphere

                Good thermal properties

(1) Heat resistance: general galvanized products typically use temperature does not exceed 230 ℃,

     reached 250 ℃ when will change, but long-term use galvanized plate at 315 ℃ environment.

(2) heat-reflective good: its reflection coefficient is hot galvanized plate twice in the summer can

     reduce the indoor temperature, reducing air conditioning electricity consumption.
     Aluminum (300G / M2): 40H / WATT / M2
     Galvalume (150G / M2): 65H / WATT / M2
     Galvanized (275G / M2): 120H / WATT / M2
     Asbestos / cement: 150H / WATT / M2

                     Good surface properties

Small and uniform spangle
     1.Color is bright silver
     2.High surface hardness (scratch is not easy to rub)
     3.A plurality of colors may be applied a semipermeable membrane

           Good paintable

Galvalume when used as a tablet or other purposes by spray coating, degreasing simply without

the need for pre-treatment or etching treatment, because of its coating and the coating has a

good combination of polarity, and hot-dip galvanizing layerIt is not.

                 Relatively light weight

Because of galvanized steel plating lighter, in the case of the same coating thickness is greater

than the developed area per ton of galvanized steel, with 0.48MM, plating 40μm (both sides),

for example, its weight and tons of steel per square expand area as follows:
Weight per square meter per ton of steel to expand the area
Substrate thickness AZ150 Z275 AZ150 Z275
0.48mm 3.94kg 4.06kg 254m2 246m2

           Corrosion mechanism

(1) physical effects
     Aluminum zinc coating on the surface of steel sheet, steel plate in contact with the outside blocking

     the corrosive medium, the steel sheet eliminating the corrosive effects of corrosive media.

(2) chemical action
     Corrosion beginning, zinc portion preferential dissolution (~ -1.05V), followed by aluminum-rich partially

     dissolved (-0.9V), between last metal compound is dissolved (-0.75V), are lower than the electrode

     potential of iron (-0.44V) Therefore aluminum zinc layer protects the substrate etching priority, called a

     sacrificial anode protection.

(3) trivalent aluminum ion doped role
    Polarization resistance
    Rp (Al-Zn) = 10.5kΩ * cm2
    Rp (Zn) = 3.1kΩ * cm2
Thus slowing the corrosion reaction speed