Q345 S550GD Galvanized Steel Coil DX51D+Z DX54D+ZF SECC DX51D+Z Gi Sheet Coil

Thickness	0.10~6mm
Width	Galvanized steel strip:24-600 mm; galvanized steel coil:600-1250mm
Coil weight	Usually is 3-4.5 tons,the max coil is 10 tons
Zn coating	0.1-0.8 mm is 30-150 g/m2; 0.8-1.5 mm is 30-180 g/m2;1.5-6.0 mm is 30-275 g/m2
Coil ID	600-1500 mm,Normal width is 91 4/1000/1219/1250/1500 mm
Steel grade	DX51D,DX52D,DC01,DC02,SGHC
Surface	regular/mini/big/zero spangle,skin pass, chromated, unoiled, dry
Packaging	seaworthy export standard package, or according to the customers'requirement
MOQ	1 ton , We can accept sample order.
Shipment Time	Within 5-10 workdays after receiving deposit

 

 Why do galvanized coils cause white rust and black rust?

The causes of white rust and black spots are as follows: black spots are formed by further oxidation of white rust.
The main causes of white rust are:
(1) Poor passivation, insufficient or uneven passivation film thickness;
(2) The surface is not oiled or there is residual moisture on the strip surface;
(3) The surface of the strip steel contains moisture during coiling;
(4) The passivation is not completely dried;
(5) Damp or rain during transportation or storage;
(6) The storage time of finished products is too long;
(7) The galvanized sheet is in contact with or stored together with other corrosive media such as acid and alkali.