Tianjin Tianyingtai Steel Pipe Co., Ltd. is one of the most credible manufacturers and suppliers of erw steel pipes for city construction in China. Welcome to consult the quotation and import cheap erw steel pipes for city construction made in China here from our factory.
Product Info
The biggest difference between ERW steel pipe and seamless steel pipe is that ERW has a welded seam, which is the key to the quality of ERW steel pipe. The modern ERW steel pipe production process and equipment, due to the unremitting efforts of the international, especially the United States and many years, the seamlessization of ERW steel pipe has been satisfactorily resolved. Some people have divided the seamlessness of ERW steel pipes into geometric seamless and physical seamless. Geometric seamlessness is to remove the internal and external burrs of the ERW steel pipe. Due to the continuous improvement and improvement of the structure and cutter of the inner burr removal system, the removal of the inner burr of the large and medium diameter steel pipe has been well treated. The inner burr can be controlled at about -0.2mm to about 0.5mm. Physical seamlessness means that there is a difference between the metallographic structure inside the weld and the base metal, which leads to a decrease in the mechanical properties of the weld zone, and measures need to be taken to make it uniform and uniform. The high-frequency welding heat process of the ERW steel pipe causes a temperature distribution gradient near the edge of the tube blank, and forms a melting zone, a semi-melting zone, an overheated structure, a normalized zone, an incomplete normalized zone, and a tempered zone. In the superheated zone structure, the austenite grains grow sharply due to the welding temperature above 1000 °C, and a hard and brittle coarse crystal phase is formed under cooling conditions, and the existence of a temperature gradient causes welding stress. In this way, the mechanical properties of the weld zone are formed to be lower than that of the base metal. The physical seamlessness is to heat the weld zone to AC3 (927 ° C) by means of a local conventional heat treatment process of the weld, and then perform 60 m. The air-cooling process with a length and speed of 20m/min is re-cooled when needed. The use of this method achieves the purpose of eliminating stress, softening and refining the structure, and improving the comprehensive mechanical properties of the heat affected zone of the weld. So far, the world's advanced ERW units have generally adopted this method to treat the welds, and have achieved good results. The high-quality ERW steel pipe can not only identify the weld seam, but also achieve a weld seam coefficient of 1, which achieves the matching of the weld zone structure with the base metal.
ERW steel pipe has the use of hot-rolled coil as raw material, and the wall thickness can be controlled to about ±0.2mm. The second end of steel pipe is in accordance with American APl standard or GB/T9711.1 standard, trimming beveling, fixed length delivery, etc. advantage. In recent years, various natural gas pipeline network engineering and gas companies have widely adopted ERW steel pipes as the main steel pipes of urban pipe networks.
Classified by purpose
According to the application, it is divided into general welded pipe, galvanized welded pipe, blown oxygen welded pipe, wire casing, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welding thin wall pipe, electric welding special pipe and spiral welded pipe.
General welded pipe
Generally welded pipes are used to deliver low pressure fluids. Made of Q195A, Q215A, Q235A steel. It can also be made of other mild steel that is easy to weld. The steel pipe is subjected to experiments such as water pressure, bending and flattening, and has certain requirements on the surface quality. Usually, the delivery length is 4-10 m, and the fixed length (or double rule) is often required for delivery. The specifications of the welded pipe are expressed by the nominal diameter (mm or inch). The nominal diameter of the welded pipe is two kinds of ordinary steel pipe and thick steel pipe according to the specified wall thickness. The steel pipe is divided into two types according to the pipe end form: threaded and unthreaded.
Galvanized steel
In order to improve the corrosion resistance of the steel pipe, the general steel pipe (black pipe) is galvanized. The galvanized steel pipe is divided into two types: hot-dip galvanizing and electro-galvanizing. The hot-dip galvanizing layer is thick and the cost of electro-galvanizing is low.
Blowing oxygen welded pipe
It is used as a pipe for oxygen blowing in steelmaking. It is generally used for welded steel pipes of small diameter. The specifications range from 3/8 inch to 2 inch. Made of 08, 10, 15, 20 or Q195-Q235 steel strip. For corrosion protection, some are aluminized.
Wire casing
It is an ordinary carbon steel electric welded steel pipe used in concrete and various structural power distribution projects. The commonly used nominal diameter is from 13-76mm. The sleeve of the wire sleeve is thin, and most of it is coated or galvanized. Cold bending test is required.
Metric welded pipe
The specification is in the form of a seamless pipe. The welded steel pipe is expressed by the outer diameter * wall thickness and millimeter. It is welded by the tropical or cold belt of ordinary carbon steel, high quality carbon steel or ordinary low alloy steel, or cooled by tropical welding. Made by dialing method. Metric welded pipes can be divided into general and thin walls, commonly used as structural parts, such as transmission shafts, or to transport fluids. Thin walls are used to produce furniture, lamps, etc., to ensure the strength and bending test of steel pipes.
Roller tube
Used for belt conveyor electric welding steel pipe, generally made of Q215, Q235A, B steel and 20 steel, diameter 63.5-219.0mm. The pipe bending degree, the end surface should be perpendicular to the center line, and the ellipticity has certain requirements, and the water pressure and flattening test are generally performed.
Transformer tube
It is used to manufacture transformer heat pipes and other heat exchangers. It is made of ordinary carbon steel and requires flattening, flaring, bending and hydraulic testing. Steel pipes are delivered in fixed lengths or multiples, which have certain requirements for the bending of steel pipes.
Shaped tube
Square tubes, rectangular tubes, hat tubes, and steel tubes for empty rubber doors and windows, which are welded by ordinary carbon-bonded structural steel and 16Mn, are mainly used as agricultural machinery components, steel window doors, and the like.
Electric welding thin wall tube
Mainly used to make furniture, toys, lamps and so on. The thin-walled tubes made by the current stainless steel belts are widely used, such as high-grade furniture, decoration, fences and the like.
Spiral welded pipe
It is made by rolling a low carbon carbon structural steel or a low alloy structural steel strip into a tube blank at a certain angle of a helix (called a forming angle), and then welding the pipe joint, which can be produced by using a narrow strip steel. Large diameter steel pipe. Spiral welded pipe is mainly used for oil and natural gas transmission pipelines, and its specifications are expressed by outer diameter * wall thickness. Spiral welded pipes are single-sided welded and double-sided welded. The welded pipe shall ensure that the hydraulic test and the tensile strength and cold bending performance of the weld are in compliance with the regulations.
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