Fe-Zn Galva-annealed Steel Sheet (GA)
Galva-annealed steel sheet offers significant improvements in weldability and paintability by undergoing a simple pre-treatment process. After the coating process a special heat treatment forms an alloy layer between the galvanized layer and the metal base.
The weldability of galvanized sheet is drastically compromised because of the absorption of zinc coating onto the welding electrode. Galva-annealed plate improved its weldability significantly thanks to the high melting point of FeZn alloy on the surface, which prevents electrode contamination.
Greater peeling resistance
Due to exceptional paint adhesiveness resulting from the formation of alloy layers, the peeling resistance during the bending and folding treatment is greatly enhanced, compared to regular hot-dipped sheet.
Superior paint adhesiveness and corrosion resistance
The rough alloy layers of the galva-annealed sheet surface facilitates the reaction to the pre-treatment (phosphate and chromate treatment), improving paint adhesiveness and corrosion resistance.
Improvements in powdering
The FeZn alloy layer generally displays a high level of hardness and low ductility, causing the alloy layer on the surface to peel off as powder during deep drawing. Our #3CGL uses the high frequency induction heat method during the heat treatment that follows the coating phase, which drastically lowers the degree of powdering, presenting an elegant steel surface.
Powdering can be improved if a low coating material (F 10 or lower) is used during deep drawing.
Finish and Application
Various after-treatments are available for different applications.
Oiling : Car parts, products that require more machinablity
Chromate treatment : Home appliances, easy to paint on
Organic Coating : Corrosion resistance, easy to paint on, flexible, fingerprint resistance
KS D 3506
Remarks: KS D 3053-88
JIS G 3302-98