The difference between cold galvanizing and hot galvanizing
1.The production process is different: cold galvanizing is to use the electrolysis equipment to remove the oil after the oil is removed, picking up the components into the bulk of the zinc salt, and connect the negative electrode of the electrolysis equipment, and place the zinc plate on the opposite side of the workpiece. Connecting to the positive electrode of the electrolysis device, turning on the power, and using the current to move from the positive electrode to the negative electrode, the zinc is gradually plated with the appearance of the metal wire mesh. The production speed is slow, the coating is uniform, and the thickness is thin, usually only 3μm~.15μm, and it will rust in a few months.
Hot-dip galvanizing is to immerse the workpiece in the zinc liquid which is degreased, pickled, dipped, dried and then immersed in a person to heat and melt. The production speed is fast, the coating is thick but uneven, and the market allows a minimum thickness of 45um, up to 300μm. The color is darker, consumes more zinc metal, and has good corrosion resistance. Hot galvanizing can be maintained for several decades in an outdoor environment.
2.Different brightness: cold galvanized appearance is bright, silvery white luster; hot-dip galvanized surface is not cold galvanized and delicate, slightly black, color like "lead", so sometimes hot-dip galvanized wire is called " lead wire". Based on this feature, we can identify them specifically from the color.
3.The amount of zinc on the top: the amount of zinc on the surface of the plated part is the weight of the zinc layer per square meter (unit: g / m2).
Cold plating (electroplating) is less, the plating thickness is 3μm ≈ 15μm, generally 4~13g/m2;
More hot-dip plating, coating thickness 45μm ~ 300um, generally 30 ~ 60g / m2, up to 300 g / m2.
Note: When evaluating the amount of zinc on the plated part, it is sometimes measured and expressed in terms of the thickness of the zinc layer (unit: mm or μm).
4.Different market prices: the price of zinc determines the price of galvanized wire, the amount of zinc on cold galvanizing is small, and the price is relatively cheap.
5.Corrosion resistance and use environment: cold galvanizing has poor corrosion resistance, while hot galvanizing has good corrosion resistance.
Cold galvanizing is mainly used for anticorrosion of various steel products and structures. It is more suitable for repair work. It can be restored to its original state only after repairing the damaged surface of the steel. The effect of cold plating is the same as that of anti-rust oil.
Hot-dip galvanizing is galvanizing under hot dip conditions (that is, melting pure zinc into zinc solution) (and then immersing the plating parts in zinc liquid), having uniform plating, strong adhesion, not easy to fall off, and corrosion resistance. Strong, long service life and so on.
PREVIOUS： Surface Treatment Process Of Wire Mesh
NEXT：What is the use of manganese in stainless steel filter meshs?
