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Introduction to Galvanized Steel Pipe Process

Galvanized pipe is a steel pipe with a hot-dip or electroplated coating on its surface. Galvanizing can increase the corrosion resistance of steel pipes and extend their service life. This article introduces the process characteristics of galvanized pipes:


1. Optimization of Sulfate Zinc Plating
The biggest advantage of sulfate zinc plating is its current efficiency of up to 100% and fast deposition rate, which is unparalleled by other zinc plating processes. Due to insufficient crystallinity of the coating, poor dispersion and deep plating ability, it is only suitable for electroplating of pipes and wires with simple geometric shapes. The traditional sulfate zinc plating process is optimized by the sulfate zinc plating process. Only the main salt Zinc sulfate is retained, and the other components are discarded. Add an appropriate amount of iron salt to the new process formula to form a zinc iron alloy coating from the original single metal coating. The restructuring of the process not only promotes the advantages of high current efficiency and fast deposition rate of the original process, but also greatly improves the dispersion ability and deep plating ability. In the past, complex parts could not be plated, but now both simple and complex parts can be plated, and the protective performance is improved by 3-5 times compared to single metals. Production practice has proven that for continuous electroplating of wires and pipes, the grain size of the coating is finer, brighter, and the deposition rate is faster than before. The coating thickness meets the requirements within 2-3 minutes.

2. Conversion of Sulfate Zinc Plating
Only Zinc sulfate, the main salt of sulfate zinc plating, is retained for sulfate electro galvanized iron alloy. Other components such as Aluminium sulfate and alum (Potassium alum) can be removed by adding sodium hydroxide to form insoluble hydroxide precipitation during the treatment of the plating solution; For organic additives, powdered activated carbon is added for adsorption and removal. The test shows that it is difficult to completely remove Aluminium sulfate and Potassium alum at one time, which has an impact on the brightness of the coating, but it is not serious, and can be consumed with it. At this time, the brightness of the coating can be restored to the solution through treatment, and the conversion can be completed by adding the content of components required by the new process.
3. Fast deposition rate and excellent protective performance
The current efficiency of the sulfate electroplating zinc iron alloy process is as high as 100%, and the deposition rate is unparalleled in any galvanizing process. The operating speed of the fine tube is 8-12 m/min, and the average coating thickness is 2 m/min, which is difficult to achieve in continuous galvanizing. The coating is bright, delicate, and pleasing to the eye. Tested according to the national standard GB/T10125 "Artificial Atmosphere Test - Salt Spray Test" method, 72 hours, the coating is intact and unchanged; After 96 hours, a small amount of white rust appeared on the surface of the coating.
4. Unique clean production
The galvanized pipe adopts the sulfate electroplating galvanized iron alloy process, which is characterized by perforation between the production line slot and the slot, without any solution entrainment or overflow. Each process in the production process consists of a circulating system. The solutions in each tank, including acid-base solution, electroplating solution, discharge and passivation solution, are only recycled and reused without leakage or discharge to the outside of the system. The production line only has 5 cleaning tanks, which are regularly discharged through cyclic reuse, especially in the production process where there is no wastewater generated after passivation without cleaning.
5. The particularity of electroplating equipment
The electroplating of galvanized pipes, like the electroplating of wire, belongs to continuous electroplating, but the equipment used for electroplating is different. A plating groove designed for iron wire with its slender strip characteristics, the groove body is long and wide but shallow. During electroplating, the iron wire protrudes from the hole in a straight line shape

Post time: Jun-20-2023