The common steel sheets is often rust, but if people do the galvanization on the surface of steel sheets, like galvanized steel roofing sheet, then the surface will not be oxide etched and its service life will be prolonged.
As an active metal, zinc is easy to be oxidized. The zinc oxide is not the loose powder like ferric oxide,but a tense surface which could prevent the further oxidation inside.
When research related information, CAMELSTEEL finds that if people galvanize the metal surface which is less active than zinc,like iron, the first corroded metal is zinc instead of iron when it has electrochemical corrosion. That is because the zinc oxide is more tense than iron oxide. When the surface of galvanized steel sheet is destroyed and reveal the internal iron surface, as zinc is more lively than iron, it will be oxidized before the iron according to the principle of chemical battery principle, thus protecting the iron layer will not be damaged.
CAMELSTEEL Main product:
A prepainted galvanized steel coil (PPGI)
B prepainted gavalume steel coil (PPGL)
C galvanized and galvalume/aluzinc steel coil (GI & GL)
D prepainted galvanized steel plate and roofing tiles