Galvanized wire in the use of a period of time, the surface of the galvanized layer will peel off, fall, so it affects the beauty of galvanized wire, only to let the surface of the galvanized layer all removed, after polishing, re-coating, so as to ensure that the galvanized wire more long-term use.
First of all, the need for sodium hydroxide 200~300g/L sodium nitrite 100~200g/L water to add to 1L so that you can remove the more demanding parts and metal wire and so on. The treatment temperature is 100℃, and the time is until the purification.
The protection of zinc coating on iron matrix has two principles: on the one hand, although zinc is more active and easy to oxidize than iron, but its oxide film is not as loose and compact as iron oxide. The dense oxide layer formed on the surface inhibits the further oxidation of zinc in the interior. Especially after the passivation of galvanized layer, the surface of the oxide layer is more thick and dense, itself has a high oxidation prevention.
On the other hand, when the surface of the galvanized layer is damaged, exposing the inner iron matrix, because zinc is more active than iron, at this time, zinc bears the role of sacrificing zinc anode, zinc will be oxidized before iron, so as to protect the iron layer will not be damaged.
Post time: 18-03-22