The difference between hot dip galvanizing and pre-galvanizing
What is hot dip galvanizing?
Hot-dip galvanizing (galvanizing), also called hot-dip galvanizing and hot-dip galvanizing: is an effective method of metal anti-corrosion and is mainly used for metal structural facilities in various industries. It is to immerse the rust-removed steel parts into molten zinc liquid at about 500°C, so that the zinc layer is attached to the surface of the steel components, thereby achieving the purpose of anti-corrosion. To make galvanized steel using this method, we need to follow 4 steps: surface cleaning, fluxing, hot dip plating and cooling.
1. Principle
Pre-galvanizing is to chemically clean the steel and then deposit a layer of zinc on the surface of the steel through electrolysis. Hot-dip galvanizing is to immerse the steel in molten zinc liquid first, so that the surface of the steel is covered with a layer of zinc-iron alloy.
2. Production process
Pre-galvanizing is to process steel through continuous oxidation annealing, electrostatic galvanizing and other processes. The production speed is fast, automatic production can be realized, the process operation is simple, and the environmental protection is good. Hot-dip galvanizing requires the steel to be pickled, washed and then dip-plated, and the production speed is relatively slow.
3. Anti-corrosion performance
Although pre-galvanized has the function of preventing rust, there is still a certain gap compared with hot-dip galvanizing. Hot-dip galvanizing can form a thick zinc-iron alloy layer on the surface of the steel, which has better oxidation resistance and better anti-corrosion performance, and can protect the steel from rusting for a long time. The anti-rust ability of pre-galvanized steel is relatively poor and can only extend the service life of steel to a certain extent.
4. Cost
In terms of cost, the production process of pre-galvanizing is simpler and does not require subsequent processing, so the manufacturing cost is lower than hot-dip galvanizing. However, from the perspective of service life, hot-dip galvanizing can protect steel from rusting for a long time. Therefore, for some occasions with long-term use and high anti-corrosion requirements, it is recommended to choose hot-dip galvanized products.
There are some differences between hot dip galvanizing and pre-galvanizing processes. Understanding these differences will allow us to choose the most appropriate methods and products for your project. In summary, it is always necessary to choose the best galvanized steel product among the various options available in the market.
