A galvanized pipe is also called a galvanized steel pipe. Galvanized steel pipe can increase the service life of the steel pipe and prevent rust to a certain extent. This encyclopedia will introduce the classification, main uses, and process characteristics of galvanized steel pipes.
Classification
1. Hot-dip galvanized steel pipe. Let the molten metal react with the iron matrix to produce an alloy layer, allowing the matrix and coating to bond. Hot-dip galvanizing must first pickle the steel pipe to remove the iron oxide on the surface of the steel pipe. After pickling, it must be cleaned with an aqueous solution of ammonium chloride or zinc chloride and then sent to a hot-dip tank for hot-dip galvanizing. The coating of hot-dip galvanizing is relatively uniform, has strong adsorption capacity, and has a long service life.
2. Cold galvanized steel pipe. Cold galvanizing is electro-galvanizing. The amount of galvanizing is relatively small, and its corrosion resistance and service life are much worse than hot-dip galvanized steel pipes.
3. Hot-dip galvanized steel pipe. The zinc-iron alloy layer formed by the reaction between the steel pipe and the plating bath, the alloy layer, the pure zinc layer, and the steel pipe are integrated, and the corrosion resistance is relatively strong.
4. Cold galvanized steel pipe. The zinc layer and the steel pipe are independently layered. The zinc layer is relatively thin. The zinc layer is simply attached to the surface of the steel pipe. The zinc layer is easy to fall off. Therefore, cold-dip galvanized steel pipes are not allowed to be used as water pipes.
Main uses: Galvanized steel pipes are usually used to loosen gas and heat. Galvanized steel pipes are also used as water pipes. However, after a few years of use, a large amount of rust and scale will be produced. The yellow water flowing out will not only contaminate the sanitary ware but also cause Bacteria to grow in the lining. Rust will also cause the heavy metal content in the water to exceed the standard, further endangering human health. The Ministry of Construction of our country has stipulated that the use of galvanized steel pipes as water pipes will be prohibited from 2000.
Process characteristics: The advantage of sulfate galvanizing is that the current utilization rate reaches 100% and the deposition rate is very fast. However, because the coating crystallization is not fine enough, the deep plating ability is poor, and it is only suitable for pipes and wires with simple geometric shapes. After process improvement, iron salts were added to the original solution, which not only inherited the advantages of traditional sulfate galvanizing but also enhanced the ability of deep plating. After continuous improvement, the coating grains used for wires and pipes are more delicate and shiny than before.
Post time: Jan-30-2024