R&D
POSMAC
HOMEPosMAC3.0(POSCO Magnesium Aluminium alloy Coating product) is a ternary alloy coated steel(Zn- 3%Mg- 2.5%Al)
with high corrosion resistance developed with POSCO’s own technology.
PosMAC® 3.0 is the registered trademark of POSCO.
PosMAC3.0 is a corrosion resistant products that is 5 to 10 times stronger resistance than that of a normal hot-dip
galvanized steel sheet(GI, GI(H)) with the same coating weight.
PosMAC3.0 has an excellent cross-section corrosion resistance; normal thick plating products can be replaced with this product.
The same processing, assembly and painting process can be applied to PosMAC3.0 as one would apply to GI.
PosMAC3.0 is superior to GI in corrosion resistance on flat, machined,
cross-section parts and is superior to galvalume in cross-section corrosion resistance.
| Quality items | PosMAC3.0 | GI | Galvalume | |
|---|---|---|---|---|
| Hardness(Hv) of coating layer | 110~130 | 60~80 | 80~100 | |
| Friction characteristics | ◎ | × | △ | |
| Corrosion resistance |
Flat sheet | ◎ | △ | ◎ |
| Bending | ◎ | △ | △ | |
| Cup | ◎ | △ | ◎ | |
| Cross-section | ◎ | △ | × | |
| Chemical resistance | ◎ | △ | △ | |
| Weldability | ◎ | ◎ | ◎ | |
Corrosion resistance in cross-section parts of PosMAC3.0, is superior to that of GI(H) and galvalume.
PosMAC3.0 also gets red-rust in cross-section parts when initially exposed outdoors.
However as the time goes by, the corrosion(red-rust) area of PosMAC3.0 tends to decrease through the formation of its distinctive oxide-based material(simonkolleite).
If the thickness of PosMAC3.0 is more than 1.6t, we recommend post-treatment(catalog 19p, 22p), because it is not fully
covered by simonkolleite after 1 year.
And when the thickness of PosMAC3.0 is less than 1.6t and cross-section parts is clean without red-rust at initial construction,
it is recommended to carry out post-treatment by the option of the customers.
Note Outdoor exposure test at seosan chemical industrial complex(Oct. `12 ~ Oct. ’14, Korea conformity laboratories)