SSAW Pipe

　 　Induction welding 　　The two main aspects of HF welding are processes and power supplies. Each of these can be broken down further into subcategories. Processes. The two HF welding processes are HF contact and HF induction. In both processes, the equipment that provides the electrical current is independent from the equipment that supplies the forge pressure. Also, both HF methods can employ impeders, which are soft magnetic components located inside the tube that help to focus the weld current in the strip edges. 　　Contact welding description 　　HF Induction Welding. In the case of HF induction welding, the weld current is transmitted to the material through a work coil in front of the weld point. The work coil does not contact the tube--the electrical current is induced into the material through magnetic fields that surround the tube. HF induction welding eliminates contact marks and reduces the setup required when changing tube size. It also requires less maintenance than con...

　 　Boiler tubes 　　Defect localization and analysis, mainly for the defect depth 0.2 ~ 0.5mm, the length of 20 ~ 50mm superficial cracks, which causes the piercing of minute defects generated in the process, or rolling the first and second plurality of specifications by trauma, Four planes during rolling 20g high-pressure boiler tube by the inner surface of the oxide residue effects formed in the slide and scarring defects, these defects after rolling reduction of squash and stretch Zhang aggravated. 　　Through the high-pressure boiler tube double length number tracking found that injury concentrated in the steel tube end report first, twice-foot (from the pipe end within 25m), is closely related to the capillary head borax oxide accumulation, small-diameter steel pipe defect in the front of the capillary the higher the ratio of the rolling zone appears. Through the above analysis we can draw the following conclusions: 　　(1) the presence of perforated capillary end in addition to ...

　　Hot rolling, as the name suggests, the temperature of rolled piece is high, so the deformation resistance is small to achieve large deformation. Take rolling of steel plate for example, the general thickness of continuous casting slab is about 230mm, and after roughing mill and finishing mill, the final thickness is 1~20mm. At the same time, due to the small thickness ratio of steel plate, the dimension accuracy is relatively low, it’s not easy to cause shape problem. 　　 Advantage 　　It can destroy the microstructure of ingot casting, grain refinement of steel and eliminate microstructure defects, so that make steel structure compact and improve the mechanical properties. This improvement is mainly reflected in the rolling direction, so that the steel no longer is isotropic; Formation of bubbles, cracks and loose when pouring can also be welded under high temperature and pressure. 　　The technological process of hot-rolled seamless pipe 　　round billet→heating→perforation→extrus...

　　 Seamless steel pipe wall thickness inspection 　　Micrometer is the main tool that is adopted. When you check, left hand holds the micrometer stand, with right hand rotation induced wheel, and the wire rod should be coincident with the diameter of the measuring point. Once found that the wall thickness is not qualified, it should be marked in time. 　　Outside diameter, ellipse of seamless steel pipe inspection 　　Calipers, vernier caliper should be taken. The caliper should be perpendicular to the axis of the steel pipe in checking, measuring the maximum and the minimum point when the pipe rotated slowly. Founding the outer diameter of large or small, you should mark it in time. 　　Seamless steel tube length inspection 　　The steel tape can be measured directly by metallic tape. 　　Bending inspection of seamless steel tubes 　　With the tools of level, feeler and line. 　　End profile inspection 　　At two ends of the steel tube should be cut into specified angle and remove bu...

　　 Cold rolling seamless pipe 　　Cold rolled seamless pipe is a seamless steel pipe for high dimensional accuracy and good surface finish. Cold rolled seamless pipe in addition to include the general steel, low and medium pressure boiler tube, high-pressure boiler tubes, alloy steel pipe, stainless steel pipe and oil cracking tube, also includes carbon thin wall steel pipe, alloy thin wall steel tube, thin-walled stainless steel pipe and special-shaped steel tube. The diameter of cold rolled seamless steel pipe is 6mm, wall thickness is 0.25mm, while the diameter of thin-walled tube can be 5mm, wall thickness can less than 0.25mm. The dimensional accuracy of cold rolling is higher than that of hot rolling. 　 　Hot rolling seamless pipe 　　Hot rolling is relative to the cold rolling. Cold rolling carries on rolling below the temperature of recrystallization, and hot rolling is above the recrystallization temperature. Hot rolled seamless steel pipe is generally divided into low, medi...

　　There are three common methods for forming welded steel pipes: 　　1. Single radius forming method 　　The single-radius roll forming method has three methods: a circumferential bending forming method, an edge bending forming method, and a center bending forming method. The single radius forming method is: the hole type is composed of a single radius, and the forming machine horizontal roller and vertical roller are alternately arranged, and the strip is formed. From the middle of the horizontal roller and the vertical roller, the flat plate is gradually bent into a circular tube. 　　2. Circular bending forming method 　　The strip is bent and deformed at the same time in the whole width direction, and the bending radius of each frame is gradually reduced; the edge bending forming method starts from the edge of the strip, the bending radius is constant, and the deformation angle is gradually increased to reduce the middle portion of the strip. Width until the steel strip is rounded;...

　　The so-called seamless steel tube yield strength refers to the yield limit when the seamless steel tube yields, that is, the stress against the slight plastic deformation. External forces greater than this limit will permanently disable the part and will not recover. 　　The external factors that affect the yield strength of seamless steel tubes are: temperature, strain rate, and stress state. As the temperature decreases and the strain rate increases, the yield strength of the material increases, especially the body-centered cubic metal is particularly sensitive to temperature and strain rate, which leads to low temperature embrittlement of the steel. The effect of the stress state is also important. Although the yield strength is an essential indicator of the intrinsic properties of the material, the stress state is different and the yield strength values are different. 　　The intrinsic factors affecting the yield strength of seamless steel tubes are: bonding bond, organization, s...

　　(1) Carbon; the higher the carbon content, the higher the hardness, but the worse its plasticity and toughness. 　　(2) Sulfur; it is a harmful impurity in steel. When steel with high sulfur content is subjected to pressure processing at high temperature, it is easy to be brittle and is usually called hot brittleness. 　　(3) Phosphorus; can significantly reduce the plasticity and toughness of steel, especially at low temperatures, this phenomenon is called cold brittleness. In high quality steel, sulfur and phosphorus should be strictly controlled. However, from another point of view, the inclusion of higher sulfur and phosphorus in low carbon steel can make it easy to cut, which is beneficial to improve the machinability of steel. 　　(4) Manganese; can improve the strength of steel, can weaken and eliminate the adverse effects of sulfur, and can improve the hardenability of steel, high alloy steel (high manganese steel) with high manganese content has good wear resistance And othe...

　　 Stainless steel pipe elbow has excellent corrosion resistance, stainless steel surface thin and strong oxide film so that all stainless steel in all water quality has excellent corrosion resistance, even buried also has excellent corrosion resistance. So it is suitable for a variety of water quality, in addition to disinfection and sterilization, do not need to control the water quality, at the same time, there is no corrosion and excessive exudate, to maintain clean water quality, to prevent secondary pollution, can withstand up to 30 meters per second The impact of high water flow. The stainless steel pipe elbow has a rust point, indicating that the elbow is not purely stainless steel material is made. Rust point can be polished with ultra-fine sandpaper bright colorless paint to do after the anti-rust treatment can be used. If you do not deal with rust point, these rust points will gradually expand, affect the appearance and will shorten the elbow life. 　　Many people think tha...

　　What is the raw material required for manufacturing seamless & ERW stainless steel Pipes? Seamless Steel Pipe is made from a solid round steel ‘billet’ which is heated and pushed or pulled over a form until the steel is shaped into a hollow tube. Billets are procured both from indigenous suppliers and from abroad. HR Coils are required to manufacture ERW stainless steel pipes. 　　To identify that a pipe supplied is seamless or ERW, Simply read the stencil on the side of the pipe. If it is ASTM A53, Type S means seamless. Type F is furnace but welded, type E is Electrical resist welded. 　　What is the difference between seamless stainless steel pipe and ERW stainless steel pipe? 　　1. ERW steel pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW steel pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its c...

　　Today, Great Steel Pipe will share the connection modes of oil pipelines for all of you. Oil pipeline must use a certain connection to form a complete system. Connection methods of pipeline are mainly three categories, including screw thread, welding and flange connection. 　　When the pressure is not high, the pipe with small diameter can be connected by using screw thread this method. This connection method is very convenient, but most of the diameter of oil pipelines are generally larger, so other two connection methods are used commonly. The pipeline that DN≥50 basically uses welding method to connect. Welding has many advantages, such as convenient construction, strong, tight and saving steels. The general straight pipe or bends those parts do not need to tear down can use this method. 　　The connection of pipes and valves or other equipment (such as: pump) and the parts those need to disassemble of pipeline need to use flange to connect. In order to ensure the tightness of th...

　　Defects on the seamless steel pipe internal and external surface have a great influence on the performance of high-pressure boiler tubes using. As a leading seamless steel pipe manufacturer, Prime Steel Pipe will adopt some measures to control quality in the production process of seamless steel pipe. 　　1, Add hot ingot, billet surface and perforation of the capillary inner and outer surfaces are determined by the shortage tube outer diameter surface, remove oxide skin, eliminating the resulting scarring and other defects. 　　2, Use high-quality work, excellent mold and process for lubrication to prevent sticking during rolling of steel, defects, excessive wear and other phenomena, to eliminate the resulting straight, scratching, rolling off, cracks and other defects. 　　3, Use protective gas heat pipe. No shielding gas should be heat-treated steel shot blasting, sanding, etc. Overall, the surface of iron oxide to eliminate defects and improve surface quality and ease of surface ...

　　Straight joint steel tube structural design features 　　1. Tensile strength (σb): The maximum force (Fb) received by the sample during the stretching process, divided by the original cross-sectional area (So) of the sample (σ), is called Tensile strength (σb) in N/mm2 (MPa). It shows the maximum ability of metal data to resist damage under tensile effects. Where: Fb - the maximum force accepted when the sample is broken, N (Newton); So - the original cross-sectional area of the sample, mm2. 　　2. The yield point (σs): metal data with the phenomenon of yielding, the force of the sample during the stretching process is not added (maintained stable), the stress can continue to stretch, called the yield point. If the force attack declines, the upper and lower yield points should be distinguished. The unit of the yield point is N/mm2 (MPa). Upper yield point (σsu): the maximum stress before the sample is bent and the force is first lowered; the lower yield point (σsl): the minimum stres...

　　In the production process of welded steel pipe , quality inspection is a very importance of foundation link. In general, pipe manufacturer will use optical microscope to test weld seam. Optical microscope is light waves to deal with visible and near-visible, bunching the beam to irradiate on the object, the imaging falls on the human retina, photosensitive film or other recording system, breaking the limitations of human physiology, the visual extension to The human eye can not tell the microscopic world. It is the most important optical precision instrument used to observe, record and study the fine structure of the object being examined. 　　High-frequency welded steel pipe is using the welding method to effectively connect the metal material. When pipe manufacturers produce high-frequency welded steel pipe (such as ERW steel pipe, LSAW steel pipe, spiral welded pipe), many factors in the welding process directly affect the weld metal and heat affected area of the macrostructure an...

　　When the factories manufacture welded steel pipe , the strip is fed into the welded pipe unit, rolled by the multi-way roll, the strip is gradually rolled up to form the circular tube with the opening gap, the pressing amount of the pressing roller is adjusted so that the gap of the weld is controlled at 1 ~ And make the ends of the weld flush. If the gap is too large, resulting in reduced proximity effect, insufficient eddy current heat, weld intergranular junction failure caused by non-fusion or cracking. If the gap is too small is caused by the adjacent effect increases, welding heat is too large, resulting in weld burns; or weld seam formed a deep pit after squeezing and rolling, which affects the surface quality of the weld. 　　1.The control of welding temperature 　　The welding temperature is mainly affected by the high-frequency eddy current thermal power. According to the correlation formula, the high-frequency eddy current heat is mainly affected by the current frequency, ...

　　In the production of ERW steel pipe production,  roll units are needed. The types of weld pressure rolls, or squeeze boxes as they sometimes are called, that apply the pressure required for the weld are as varied as the welding units used to supply the heat. Squeeze boxes for rotary contact wheel welding typically have two or three roll units, with the contact wheel serving as one of the rolls. 　　The number of rolls in the weld squeeze box is proportionate to the size and shape of the product being welded. There are no hard and fast rules; however, common guidelines for round tube or pipe size ranges are as follows: 　　3/8 to 2 in. uses two-roll units. 　　1/2 to 3 1/2 in. uses three-roll units. 　　2 to 10 in. uses four-roll units. 　　Larger than 10 in. uses five or more rolls. 　　Today, much more so than in the past, many shapes--square, rectangular, hexagonal--are welded in the finished shape rather than being reshaped after being welded round. The weld boxes used for th...

　　In the ERW steel pipe production, electric resistance welding played an important role. Some customer don't know clearly about electric resistance welding, so pipe manufacturer Great Steel Pipe will share types of electric resistance welding for all of you. There are three basic types of electric resistance welding: solid state, fusion, and reflow soldering. 　　In solid state, also called thermo-compression, there are dissimilar materials with dissimilar grain structure, e.g. molybdenum to tungsten, which are joined using a very short heating time, high weld energy, and high force. There is little melting and minimum grain growth, but it has a definite bond and grain interface. Thus the materials actually are still in the solid state. The bonded materials usually has excellent shear and tensile strength, but peel strength is poor. 　　In fusion, either similar or dissimilar materials with similar grain structures are heated to the melting point (liquid state) of both. The subse...

　　Some customers would wonder why should we choose hollow section tube and which kind of would be the suitable for our project. Actually, except the ERW steel pipe and seamless type, we need to see other tube’s benefits. 　　Here are four main benefits by using hollow section pipe and you will figure out the reason. 　　First of all, hollow section tubes have a uniform strength which makes them highly durable. 　　Second, hollow section tubes are known to offer an outstanding resistance to torsion. 　　In addition, the above two points make these tubes extremely reliable. 　　What’s more, they are available with us at the most competitive prices, and are very cost-effective. 　　 http://www.xysteelpipe.com/info/Four-benefits-of-using-a-hollow-section-tube-1306-1.htm

　　According to the material science point of view, the chemical composition, physical properties, and geometry of a good metal material should be continuous, pure, and uniform. If these three aspects are insufficient or damaged, the metal material is considered to be defective. If the metal material is discontinuous in geometry (ie, not tight or uncompact or not dense), such as cracks, shrinkage, peeling, pits, delamination, pinholes, slag inclusion, etc. The metal material is considered to be a scar (abbreviated as an injury), which does not include discontinuities in chemical composition or discontinuities in physical properties. It can be seen from this that the defect contains injuries. 　　Boiler steel pipes usually use seamless steel pipes, which may also have defects and injuries during smelting and rolling. According to the introduction of the steel pipe plant, the defects of the boiler steel pipe (here mainly referred to as the injury) are mainly on the surface, and the outer ...

　　The biggest difference between water gas pipeline and galvanized steel pipe is that the former is seamed steel pipe and its pressure bearing capacity is low, the later is seamless steel pipe and its pressure bearing capacity is high. 　　Water gas pipes are constituted by welded steel pipes with thick wall, its materials are different from galvanized steel pipes. Water gas pipe is made of low-carbon steel welded pipe. those Galvanized are called galvanized iron tubes. Those non-galvanized are called black pipes. 　　Galvanized steel pipe is divided into cold galvanized steel pipe and hot galvanized steel pipe. The electroplating of hot galvanized steel pipe is relatively strong, its zinc layer is thick, and there is a blue ring logo on the head of galvanized pipe. Cold galvanized steel pipe is also made by electroplating, but it is made with less technology, and its performance is far worse, no blue logo. Cold galvanized steel pipe has been banned, hot galvanized steel pipe is promo...

　　 Carbon steel pipe is made with steel ingot or solid round steel and processed into a tubular billet by perforation, than finished with hot and cold rolled. So it can be divided into hot rolled steel pipe and cold rolled steel pipe two categories. 　　Hot rolled steel pipe can be divided into general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking tube, geological steel pipe and others. 　　Cold rolled steel pipe not only included general steel pipe, low and medium pressure boiler steel pipe, high pressure boiler steel pipe, alloy steel pipe, stainless steel pipe, petroleum cracking tube, but also included carbon thin-walled steel pipe, alloy thin-walled steel pipe, stainless thin-walled steel pipe and profiled steel pipe. 　　According to the classification of use, we can divide the carbon steel pipe into below 5 types: 　　1.Pipeline tube: Such as water or gas tube, seamless steam pi...

　　Today, Great steel pipe is introduce the standard classification and application of seamless steel pipe. 　　1.Structural seamless steel tubes(GB/T8162-2008), it’s a seamless pipe used for general structure and mechanical structure. 　　2.Fluid convey seamless steel tube(GB/T8163-2008), it’s a general seamless pipe used for conveying the water, oil, gas and other low pressure fluids. 　　3.Low and medium pressure boiler seamless pipe(GB3087-2008), it’s used for make all kinds of structural seamless steel pipe, such as low and medium pressure boiler overheated steam pipe, boiled water pipe, overheated steam pipe used for locomotive boiler, big boiler smoke pipe, small boiler smoke pipe, high-quality carbon structural steel hot-rolled and cold drawn (rolled) seamless pipe used for arch brick pipe. 　　4.High pressure boiler seamless pipe(GB5310-2008), it’s used for make high-quality carbon steel, alloy steel, and stainless heat-resistant steel seamless pipe that used for high pressure...