Cautions for surface zinc spraying on channel steel
Thermal spraying zinc sacrificial anode protection is a single layer of zinc, the corrosion rate depends only on the zinc layer thickness and dissolution rate and inorganic zinc in addition to the protection of zinc layer, the complex chemical changes generated by lithium silicate, zinc silicate, carbonate can better cover metal surface. Secondly, the high porosity of thermal sprayed zinc (3% ~ 5%), another blocking agent brushing waterborne inorganic zinc rich coating with low porosity (usually below 1%), which can be used for thermal spraying zinc surface sealants. In addition, the process of thermal spraying zinc complex, need for high temperature and high pressure and inorganic zinc spraying, brushing is can be flexible operation, the overall comparison, but low cost inorganic zinc.
In the liquid zinc galvanizing state, through physical and chemical processes is quite complicated, not only in the steel plating thick pure zinc layer, but also generate a Zn Fe alloy layer. This plating method not only has galvanized corrosion characteristics, and because of the zinc iron alloy layer. It also has strong corrosion resistance which can not be compared with galvanized. Therefore, the plating method is especially suitable for various strong acids, alkalis, fog and other corrosive environments.
Thermal spraying principle summary is the first use of high pressure air pipe and the sand blown to the surface of the metal workpiece surface to remove rust and oxide skin on the surface, at the same time by increasing the absorption for Ma thermal spray coating, and then use oxygen, acetylene or electric heat source (large workpieces with electric heating, and the type of oxygen and acetylene by heating) compressed air and special tools (gun) to ultra high speed jet atomization of zinc to the metal surface.
