Views: 109 Author: Good Du Publish Time: 2023-03-10 Origin: Site
Galvanized Steel Pipe is the steel pipe after galvanized processing process, effectively avoid steel corrosion, rust a for prolong the service life of steel pipe. Galvanized steel pipes are divided into hot galvanized and electrogalvanizing.
Hot Galvanizing Process
Hot galvanizing zinc layer is thick, electrogalvanizing cost low, but the surface is not very smooth.
Hot galvanizing pipe is made of metal liquid and iron matrix reaction to form an alloy layer, so that the matrix and coating combination. It should acid wash the steel pipe first. In order to remove iron oxide from the surface of the steel pipe, after pickling, it is cleaned with an aqueous solution of ammonium chloride or zinc chloride or a mixed aqueous solution of ammonium chloride and zinc chloride, at last sent to the hot dip plating tank.
Hot galvanizing has the advantages of uniform coating, strong adhesion and long service life. Complex physical and chemical reactions occur between the steel tube substrate and the plating solution to form a compact and corrosion-resistant zinc-iron alloy layer. As a result, it has strong corrosion resistance.
Hot galvanized steel pipe is widely used in construction, machinery, coal mine, chemical industry, electric power, railway vehicles, automobile industry, highway, bridge, container, sports facilities, agricultural machinery, petroleum machinery, exploration machinery and other manufacturing industries.
Electrogalvanizing Process
Electrogalvanizing is cold galvanizing, the mass of zinc coat is very small, only 10-50g/m2, the zinc coat is electroplated, and it is independently layered with the steel pipe base material.
Zinc coat is relatively thin, it is easy to adhere to the steel pipe substrate, and easy to fall off its corrosion resistance is much worse than hot galvanizing pipe.
Most of the countries of world prohibit the technology of Electrogalvanizing , and it shall not be used as water pipe, gas pipe.
The main material of galvanized steel pipe is carbon steel 20, 45 ; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo and so on. There are many materials of galvanized steel pipe, but in the selection of materials, carbon steel is generally appropriate, Because galvanized is mainly in order to improve the corrosion resistance of steel pipe, and the corrosion resistance of other materials is better. There are also some are not suitable for galvanized surface treatment.
Galvanized Pipe Material Requirements :
Low carbon: the higher the carbon content of the steel pipe, the higher the hardness of the steel, but the worse its plasticity and toughness. The galvanized steel pipe has high requirements for toughness, weldability and formability, and the carbon content is generally less than 0.2%.
The material should add manganese alloy element.
The material should add auxiliary elements such as niobium, titanium or vanadium: a small amount of niobium, titanium or vanadium forms fine carbide or carbonitride in steel, it will be conducive to obtaining fine ferritic grains and improving the strength and toughness of steel. In addition, adding a small amount of copper (≤0.4%) and phosphorus (about 0.1%) can improve the corrosion resistance of galvanized pipe.
The material should add a small amount of rare earth elements can desulfurization and degassing, purify steel, improve toughness and process performance.
Production Standard
How to Purchase Galvanized Pipes?
It is necessary to check in detail whether the appearance of galvanized pipe is smooth, whether there is zinc tumor or burr. In general, if the surface of galvanized pipe is free of zinc nodules and burrs, and is silver white, it is high-quality galvanized pipe
It is necessary to check in detail whether there are obvious defects in the appearance of galvanized pipes, whether the color of galvanized pipes is normal, and whether the galvanized layer is uniform.
It is necessary to check in detail whether the length and size of galvanized pipe meet the qualified standards, and whether the diameter and wall thickness of galvanized pipe meet the qualified standards.
Install Caution
When installing galvanized pipes, pay attention to protecting the galvanized coat. Do not poke the galvanized pipe with sharp objects to avoid damaging the surface of the galvanized pipe. Keep the galvanized pipe in a straight state, do not bend, and do not leave some stains or foreign bodies in the pipe, which will cause the pipe to be blocked.
Before installing galvanized pipes, check whether the pipe fittings are fully prepared. If the pipe is damaged to a certain extent, it must be replaced with a new use, and the damaged pipe cannot be used to avoid certain problems. And this kind of tube can not achieve a certain effect, and the use of time will be greatly shortened.
When the pipe is cutting, it must be more evenly, and the inner diameter of the pipe must not be reduced. After the installation of the galvanized pipe, it should be tested to whether there is a broken wire. If there is a broken wire, you should repair it in time to avoid later failure, or it will makes maintenance more troubles.
The galvanized pipe should be oiled and fastened with even force. Too much or too little force will not have a certain effect. After connecting them evenly, check whether the interfaces are fully connected. Make sure it is sealed tightly, so as to play a certain effect.
We(Shanghai Zhucheng Pipe Fittings Manufacturing Co Ltd) is professional engaged in manufacture of Steel pipe(seamless/welded), pipe fittings（butt welding, socket weld, threaded），and flanges in pipe system of all kinds of materials(carbon steel, stainless steel,alloy steel,low temp steel,pipeline steel). Bushing in Material ASTM A105 of standard ASME B16.11 is one of our conventional product. In order to get to a successful cooperation with customers, normally we are willing to provide free samples to all customers if required.(The customer should be responsible for the freight and the samples should be in common size and material)
