Galvanized pipe, also known as galvanized steel pipe, is divided into two types: hot-dip galvanizing and galvanizing. The hot-dip galvanized coating is thick, with the advantages of uniform coating, strong adhesion and long service life. The cost of galvanizing is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipe. In order to improve the corrosion resistance of steel pipes, the general steel pipes are galvanized. Galvanized steel pipe is divided into two types: hot-dip galvanizing and galvanizing. The coating is thick, the cost of galvanizing is low and the surface is not very smooth. Oxygen blowing pipe: used as steel-making oxygen blowing pipe, generally small diameter welded steel pipe, specification from 3 / 8-2 "8 kinds. For the purpose of corrosion prevention, some of them shall be effectively aluminized.

　　The comprehensive mechanical properties are good, low temperature performance can also be used, plasticity and weldability are good. It can be used as the structure, mechanical parts, building structure, general metal structure, hot rolling or normalizing state of medium and low pressure vessels, oil tanks, vehicles, cranes, mining machinery, power plants, bridges and other structures bearing dynamic loads, and can be used in cold areas under -40 ℃.

　　If the structure is strength control, Q345 can be considered. For example, the structure is stiffness control, Q235 can be considered. The price Q345 is slightly expensive, but because of its high strength, it can save materials.

　　(1) Unique clean production

　　The galvanized pipe adopts the sulfate Electrogalvanized ferroalloy process, which is that the production line groove and groove are all through through and the solution is free of any belt out or overflow. Each process of production process consists of a circulating system. Each tank solution is acid-base solution, electroplating solution, light outlet and passivation solution. Only recycle and reuse is not leaking or discharging outside the system. Only 5 cleaning tanks are set up in the production line. The production process is discharged regularly by recycling, especially the production process without waste water after passivation.

　　(2) The particularity of electroplating equipment

　　The plating of copper wire for galvanized pipe is the same as continuous plating, but the equipment for plating is different. The bath designed by the wire with its slender strip features has a long and wide but shallow groove. When plating, the wire is penetrated from the hole, and unfolds in a zigzag form on the liquid level, keeping the spacing between them. However, galvanized pipe is different from wire, which has its own unique features and its groove equipment is more complex.

　　The tank body is composed of two parts, the upper part is the plating tank, the lower part is the solution circulating storage tank, forming a groove body with the width of the upper narrow and the lower, which is like a trapezoid. In the bath, there is a channel for galvanizing pipe plating operation. Two through holes at the bottom of the tank are connected with the lower storage tank, and the plating liquid circulating reuse system is formed with the liquid pump. Therefore, the galvanized pipe is dynamic like the iron wire plating, and the plating solution of the galvanized pipe is dynamic in different places from the iron wire plating.

　　(3) Optimization of sulfate zinc plating

　　The advantages of sulfate zinc plating are that the current efficiency is up to ****, and the deposition rate is fast, which is incomparable to other galvanizing processes. Because of the lack of fine crystallization and poor dispersion and deep plating ability, it is only suitable for electroplating of simple geometry pipe and wire. The traditional process of sulfate zinc plating was optimized by the process of sulfate electrogalvanizing iron alloy, only the main salt zinc sulfate was retained, and the rest components were abandoned.

　　In the new process, a proper amount of iron salt was added to form zinc iron alloy coating. The recombination of the process not only develops the advantages of high current efficiency and fast deposition rate, but also greatly improves the dispersion and deep plating ability. In the past, complex parts can not be plated, and now simple and complex parts can be plated, and the protective performance is 3-5 times higher than that of single metal. The production practice shows that the coating grain is more refined, brighter and deposition rate is faster than the original one in continuous plating of wire and pipe. The thickness of the coating meets the requirements within 2-3 minutes.

　　(4) Transformation of sulfate zinc plating

　　The main salt zinc sulfate of sulfate zinc sulfate is retained in the sulfate Electrogalvanized iron alloy. The rest components such as aluminum sulfate and alum (potassium aluminate) can be precipitated and removed by adding sodium hydroxide to the plating solution; For organic additives, powder activated carbon was added to remove the additives.