The difference between hot-dip galvanized steel and cold-dip galvanized steel

1. The production process (process) is different: cold galvanizing uses electrolysis equipment to degrease and pickle the workpiece, then puts it into a solution composed of zinc salts, connects the negative electrode of the electrolysis equipment, and places the zinc plate on the other side of the workpiece. Connect the positive electrode of the electrolysis equipment, turn on the power, and use the directional movement of the current from the positive electrode to the negative electrode to gradually cover the surface of the workpiece with zinc. electric wire. The production speed is slow, the coating is uniform, and the thickness is relatively thin, usually only 3μm~15μm, and it will rust in a few months. Hot-dip galvanizing involves degreasing, pickling, dipping, and drying the workpiece, and then immersing it in heated and molten zinc liquid for a certain period of time, and then taking it out. The production speed is fast, and the coating is thick but uneven. The minimum thickness allowed by the market is 45pm, and the maximum thickness can be more than 300pm. The color is darker, consumes more zinc metal, and has good corrosion resistance. Hot-dip galvanizing can last for decades in outdoor environments.

2. Different brightness: cold-dip galvanizing has a bright appearance and is silver-white; hot-dip galvanizing is not as delicate and bright as cold-dip galvanizing, slightly black, and has a color like "lead", so hot-dip galvanizing wire is sometimes called "lead". Leads". Based on this feature, we can specifically identify them by color.

3. Different amounts of zinc coating: The amount of zinc coating refers to the weight of the zinc layer per square meter on the surface of the plated part (unit: g/m2). Less cold plating (electroplating), coating thickness 3μm~15um, generally 4~13g/m Hot dip plating is mostly used, and the coating thickness is 45μm~300pm, generally 30~60g/㎡, and can reach up to 300 g/m2

Note: When evaluating the amount of zinc on plated parts, the thickness of the zinc layer (unit: mm or m) is sometimes measured and expressed.

4. Market prices are different: the amount of zinc on cold galvanizing is very small, and the price is relatively cheap.

5. Corrosion resistance is different from the use environment: cold galvanizing has poor corrosion resistance, while hot-dip galvanizing has good corrosion resistance.