Introduction to hot-dip galvanized square tubes, raw materials for Metal fence products. In order to improve the corrosion resistance of steel pipes, general steel pipes are galvanized. Galvanized steel pipes are divided into hot-dip galvanized steel pipes and electro-galvanized steel pipes. The galvanized layer of hot-dip galvanized steel pipes is thick. The zinc layer thickness of the hot-dip galvanized steel pipes used by Anduda reaches 120g/square meter; but the thickness of electro-galvanized is thin, only 5-20g/square meter, so the cost is low and the surface is not very smooth; hot-dip galvanized steel pipes have smooth surfaces and excellent anti-corrosion properties; in fact, there is another kind, hot-dip galvanizing, which is the so-called post-galvanizing. After the zinc layer, the cost is high and the anti-corrosion performance is extremely strong, but the surface is not smooth and very rough.
Hot-dip galvanized pipes react molten metal 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 ammonium chloride or zinc chloride aqueous solution or a mixed aqueous solution of ammonium chloride and zinc chloride, and then sent to the hot-dip galvanizing tank. Hot-dip galvanizing has the advantages of uniform coating, strong adhesion and long service life. The steel pipe substrate undergoes complex physical and chemical reactions with the molten plating solution to form a corrosion-resistant and tightly structured zinc-iron alloy layer. The alloy layer is integrated with the pure zinc layer and the steel pipe substrate. Therefore, it has strong corrosion resistance.
- Uniformity of the galvanized layer: The steel pipe sample shall not turn red (copper-plated color) after being immersed in the copper sulfate solution for 5 consecutive times
- Surface quality: The surface of the galvanized steel pipe shall have a complete galvanized layer, and there shall be no unplated black spots and bubbles. Small rough surfaces and local zinc nodules are allowed.
- Weight of the galvanized layer: According to the requirements of Anduda Company, the galvanized steel pipe can be measured for the weight of the zinc layer, and the average value shall not be less than 120g/square meter.
- Hot-dip galvanized steel pipes are commonly used in fence series, guardrail series, and access control series. Such as SMWL01,SMMF02,SMZL01.