Hot-dip galvanized steel pipe production process knowledge

Zinc is easily soluble in acid and alkali, so it is called an amphoteric metal. Zinc changes little in dry air. In humid air, a dense basic zinc carbonate film will form on the zinc surface. In atmospheres containing sulfur dioxide, hydrogen sulfide and marine atmospheres, zinc has poor corrosion resistance. Especially in atmospheres with high temperature, high humidity and organic acids, the zinc coating is easily corroded.

Hot-dip galvanized pipe: The molten metal reacts with the iron matrix to produce an alloy layer, thereby combining the matrix and the coating. Hot-dip galvanizing is to pickle the steel pipe first. In order to remove the iron oxide on the surface of the steel pipe, after pickling, it is cleaned in an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to in a hot dip plating tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion, and long service life. Most of the processes in the north adopt the zinc-replenishing process of direct coiling of galvanized strips.
Hot-dip galvanized steel pipe: The steel pipe matrix undergoes complex physical and chemical reactions with the molten plating solution to form a corrosion-resistant zinc-iron alloy layer with a tight structure. The alloy layer is integrated with the pure zinc layer and the steel pipe matrix. Therefore, it has strong corrosion resistance.

In order to improve the corrosion resistance of steel pipes, general steel pipes are galvanized. Galvanized steel pipes are divided into two types: hot-dip galvanizing and electro-galvanizing. Hot-dip galvanizing has a thick zinc layer, while electro-galvanizing has low cost and the surface is not very smooth. Oxygen blowing welded pipe: used as oxygen blowing pipe for steelmaking. Generally, small diameter welded steel pipe is used, with eight specifications ranging from 3/8 to 2 inches. Made of 08, 10, 15, 20 or 195-Q235 steel strips, some require effective aluminizing treatment in order to prevent corrosion.
Production Process:
Galvanized strip → Uncoiling → Stretching → Coiling → Welding → Scratching → Passivation and rinsing → Zinc replenishment → Shaping → Typing logo → Cutting → Packing → Drying → Weighing.