Zinc spraying refers to the surface treatment technology of plating a layer of zinc on the surface of metal, alloy or its wide material in order to play the role of beauty and rust prevention. The main method used is hot dip galvanizing.
So what is the effect of zinc spraying on dry nodular cast iron pipe?
Because of the high carbon content of cast iron, iron-carbon alloys rust more quickly in wet conditions. If you look at pig iron in a foundry, it’s bound to be rusty on the outside. Zinc is chemically more active than iron and copper, so coating iron with zinc can protect it from corrosion. This process is especially used in the construction and shipbuilding industries, where a chemical reaction occurs when the iron is coated with zinc, which coats the iron with a protective layer of ZnC03, 3Zn (OH) 2 and the like. Reduce external corrosion to dry itself.
Zinc layer plays an extremely important role in anticorrosion performance: on the one hand, the formation of dense insoluble protective film attached to the tube wall, can greatly reduce electrochemical and microbial corrosion; On the other hand, metal zinc also has the impact resistance of plastic deformation ability, strengthen the protection of the pipeline. Zinc + asphalt anti-corrosion ability is also reflected in the interaction between the two: between zinc and cast iron and between zinc and asphalt has a good adhesion, to the pipeline and the outside world to build a complete protective barrier, and prevent anti-corrosion failure.