Seamless Steel Pipe

　　Large diameter straight seam steel pipe is more and more welcomed by petroleum and natural gas, slurry transportation, steel structure engineering and other industries for its advantages of high pressure bearing capacity, low resistance, low temperature resistance, corrosion resistance, easy installation and maintenance. 　　Description of main production process of large diameter straight seam welded pipe: 　　1. Plate prospecting: After the steel plate used to manufacture large diameter submerged arc welded straight seam steel pipe enters the production line, the whole plate ultrasonic inspection is carried out first. 　　2. Milling: Double-sided milling of steel plate edges by milling machine to achieve the required width, parallelism and groove shape. 　　3. Pre-bending edge: Pre-bending edge with pre-bending machine, so that the edge of the plate has the required curvature. 　　4. Forming: On JCO forming machine, first half of the pre-bended steel plate is stamped into "J...

　　The main feature of ordinary cold drawn seamless steel pipe is that it has no welded joint and can withstand large pressure. The product can be a very rough cast or cold-draw. 　　Cold drawn seamless steel pipe is a product that has appeared in recent years, mainly the inner hole, outer wall size has strict tolerance and roughness. 　　Cold drawn seamless steel pipe features: 　　1. The outer diameter is smaller. 　　2. High precision can be used to make small batches 　　3. Cold drawn (rolled) seamless steel pipe with high precision and good surface quality. 　　4. The cross-sectional area of cold drawn seamless steel pipes is more complicated. 　　5. The performance of cold drawn seamless steel pipe is superior, and the seamless steel pipe is relatively dense. 　　6. cold drawn seamless steel pipe partial wall situation is reduced, the inner and outer diameter can be controlled within 0.1mm according to customer requirements.

　　API Spec 5L PSL1/PSL2 Gr.b, X42/46/52/56/65/70 Seamless steel pipe for line pipe 　　ASTM A53 Gr.B Black and hot-dipped zinc-coated steel pipes welded and seamless 　　ASTM A106 Gr.B Seamless carbon steel for high temperature service 　　ASTM SA179  Seamless cold-drawn low-carbon steel heat exchanger and condenser tubes 　　ASTM SA192  Seamless carbon steel boiler tubes for high pressure 　　ASTM SA210  Seamless Medium-carbon boiler and superheater tubes 　　ASTM A213 Seamless alloy-steel boiler, superheater, and heat-exchanger tubes 　　ASTM A333 GR.6 seamless and welded carbon and alloy steel pipe intended for use at low temperatures. 　　ASTM A335 P9,P11,T22,T91Seamless ferritic alloy-steel pipe for high-temperature service 　　ASTM A336 Alloy steel forgings for pressure and high-temperature parts 　　ASTM SA519 4140/4130 Seamless carbon for mechanical tubing 　　API Spec 5CT J55/K55/N80/L80/P110/K55 Seamless steel pipe for casing 　　DIN 17175 Seamless steel tube f...

　　During the welding process of X80 pipeline steel, the microstructure and properties of the heat-affected zone will be greatly changed due to the heat of the welding process, especially the microstructure and properties of the coarse-grained heat-affected zone change the most. Using thermal simulation technology, engineering test method and microscopic analysis method were used to study the influence of preheating temperature on the charpy impact toughness of the coarse-grained heat affected zone of X80 pipeline steel, and the reasons were analyzed to determine the preheating of the pipeline under small line energy. Temperature. It is considered that welding under small line energy, preheating before welding is beneficial to the toughness of the coarse grain zone. When the field welding line energy is 10 kJ/cm, it is recommended that the preheating temperature before welding is 150 °C; Welding under energy, preheating before welding has no benefit to the toughness of the coarse grain ...

　　What is galvanized steel pipe ? 　　Galvanized pipes, also known as galvanized steel pipes, are divided into hot-dip galvanizing and electro-galvanizing. The hot-dip galvanizing galvanized layer is thick, with uniform plating, strong adhesion and long service life. The cost of electroplating is low, the surface is not very smooth, and its corrosion resistance is much worse than that of hot-dip galvanized pipes. 　　1. The surface of the steel pipe is more durable with anti-embroidery treatment, and it will not be oxidized too quickly, and will not form white rust on the steel pipe; 　　2. The steel pipe is fully protected. After heating, each part of the steel pipe is plated with zinc, and the concave and convex parts are protected; 　　3, with anti-corrosion and wear-resistant features, let the steel pipe use longer; 　　4. Since zinc has been plated on the outside of the steel pipe, the time for oiling or lacquering outside is omitted, and the construction is more convenient; 　　5...

　　Seam pipe refers to the strip or plate bending round, square and other shapes and then welded into the surface jointed pipe. Seam pipe is using a blank plate or strip. 　　With the advancement of high-quality steel rolling production as well as the rapid development of welding and inspection techniques, and continuously improve the quality of welds, pipe joints increasing varieties and specifications, and in more and more areas instead of seamless steel tubes. Seam pipe is lower than seamless steel pipe on cost, high production efficiency. 　　According to different welding methods can be divided arc welded pipe , high-frequency or low frequency electric resistance welded pipe, gas pipe, stove pipe, Bundy tubes. 　　Press seam shape classification can be divided into longitudinal and spiral welded pipe. 　　By end-use is divided into general welded pipe, galvanized pipe, oxygen blowing pipe, wire casing, metric pipe, roller tube, deep well pump tube, automotive tube, transformer tube...

　　In the process of anti-corrosion construction of oil (gas) pipelines, the surface treatment of steel pipes is the key factor determining the service life of pipelines. One of them is the premise that the anti-corrosion layer and the steel pipe can be firmly combined. According to the research institute's verification, the life of the anti-corrosion layer depends on the coating type, coating quality and construction environment. The surface treatment of the steel pipe affects the life of the anti-corrosion layer by about 50%. Therefore, it should be strictly in accordance with the anti-corrosion layer specification. The requirements of the surface of the steel pipe are continuously explored and summarized, and the surface treatment method of the steel pipe is continuously improved. 　　1. cleaning 　　Use solvent and emulsion to clean the surface of steel to remove oil, grease, dust, lubricant and similar organic matter, but it can not remove rust, scale, flux, etc. on the surface...

　　A seamless carbon steel pipe has many uses, thanks to the tough and versatile nature of carbon steel. This pipe is seamless, so it tends to have better durability and strength, making it useful for construction work. Many heat-transfer systems use a seamless carbon steel pipe network to the hot or cold liquid or gas in an area. The petroleum industry uses this pipe to carry large amounts of petroleum from the ground to the surface, and this pipe also is commonly used to transfer the petroleum to other places. This pipe is easier to form and bend than other carbon steel pipes, so it also can be used in places where custom angles and shapes are needed. 　　Many large structures use pipes in the deep foundation, the section that is underground. If a seamless carbon steel pipe is used, then it is driven into the ground by a large machine and may be filled with concrete after it is pile-driven to protect the pipe and make it even sturdier. This type of pipe generally is very durable and d...

　　At present, the same polishing process on the market is basically suitable for the polishing process of stainless steel pipes . The stainless steel pipe series derived from the 304 series has good adaptability to the surface polishing process, and the processing effect is very excellent. The current polishing type grades are mainly divided into: outer surface #400/#600, hair surface and matte surface. 　　1, oil brush drawing 　　The stainless steel pipe processed by oil brush is mainly used for the decoration of elevators and some home appliance furniture. The effect after oil brushing and drawing is very beautiful, and has good decorative effect. The oil sanding wire is also divided into filament and short wire. For the decoration of hair accessories such as elevators, filaments will be selected, while small appliances or some furniture decorations will choose short filaments. 　　2, dry grinding and drawing 　　Dry-brushed wire drawing does not hit the processing equipment, and th...

　　The seamless steel pipe is expressed by the method of outer diameter, wall thickness and thick-walled seamless pipe, which are mainly used for mechanical processing, coal mine, hydraulic steel and the like. The material of the thick-walled seamless steel pipe is divided into 10#, 20#, 35#, 45#, 20Cr, 40Cr, 42CrMo, 16Mn, 27SiMn, 12Cr1MoV, 10CrMo910, 15CrMo, 35CrMo and the like. 　　1. The seamless pipe must be worn with labor protection products before pickling. For the working environment on site, detailed inspection is also carried out, mainly to check whether the sling of the steel pipe is in good condition, and the work can be carried out after the confirmation is completed. 　　2. When the seamless tube is pickled, the pickling is mainly acid washing with hydrochloric acid, and the content of hydrochloric acid is generally 18% to 20%. 　　3. The staff also needs to know the acid concentration and temperature and the tonnage of the acid pickling pipe before the operation. 　　4. F...

　　 LSAW steel pipe weld appearance basic requirements: 　　Straight seam steel pipe before NDT, weld visual inspection should meet the requirements. General requirements for straight seam steel pipe weld appearance and surface quality of welded joints are as follows: Welding should look good shape, width of each side groove edge 2mm overshadowed appropriate. Fillet weld leg height should meet the design requirements, the shape should be smooth transition. 　　Welded joint surface requirements: 　　(1) Does not allow cracks, lack of fusion, pores, slag, spatter exist. 　　(2) The design temperature is below -29 degrees pipes, stainless steel and hardened alloy steel pipes tend to be larger weld surface, without undercut. Other material pipe weld undercut depth should be greater than 0.5mm, continuous undercut length should not exceed 100mm, and both sides of the weld undercut always grow up to 10 percent of the entire length of the weld. 　　(3) Shall not be lower than the surface of t...

　　ERW (ERW straight seam welded steel pipe) is a hot-rolled coil after molding machine, the use of high-frequency current skin effect and proximity effect, so that the edge of the tube is heated to melt under the action of squeezing rollers pressure welding to achieve production. 　　High frequency resistance welding method used in pipe production of the 1950s. Over the past decade, the production technologies are maturing, continuously improve product quality. 　　First, ERW steel pipe used in the production of raw material quality has been significantly improved, the steel component design of the low C, low P, S, micro-alloying; smelting process smelting, ladle refining, vacuum degassing, continuous casting and other new using technology; ERW pipe - ERW rolling process controlled rolling, controlled cooling technology enables the use of medium and large caliber ERW steel pipes hot strip appearance of size, appearance quality, physical and chemical properties greatly improved. On beh...

　　In the caliber of longitudinal welded pipe production line is set welding, finishing, pipe processing, pipe casing heat treatment in one of the pipe production line. ERW steel pipe line which introduced the German SMS Meer company developed molding equipment and technology, and equipped with the world's most advanced non-destructive testing equipment, high-frequency welding equipment, heat treatment of welding equipment. 　　The welding of forming steel pipe is the core part of welded pipe line, the quality of welding directly determines the qualified rate of the product. With the power components and power electronics technology continues to develop, as well as heating, melting, welding equipment to promote the demand for induction, induction welding equipment technology has also been an unprecedented opportunity for development. Power components from the tube to the SCR, MOSFET to IGBT gradually adopted, induction device power, frequency is also gradually increased. 　　ERW pi...

　　At present, ordinary fluid on the market with the general Longitudinal Welded Pipe is generally used in high-frequency resistance welding production, which is characterized by high production efficiency, weld heat affected zone is small, low quality requirements on the bonding surface, but the molding quality requirements, forming process Any change in the shape of the V-shaped opening may cause welding quality problems. 　　Rolling groove processing is the use of grooved joints as pipe fittings when the pipe pretreatment process. Its operating principle is the use of roll groove rolling machine driven rotating pipe, pipe radial direction of the follow-up pressure roller radial pressure applied to the use of the structure of the pressure roller welded pipe in a fixed position of cold out a specified groove. 　　A "roll groove cracking" is the root cause of the weld strength is not enough, coupled with rolling groove processing of the severe deformation, resulting in weld st...

　　The quality of welded pipe depends on the quality of welding. The quality of welding is not only directly related to the quality of the tube, especially with the design of the forming roll, the forming process, the choice of welding parameters. These factors with the equipment to adjust the state and the rapidly changing, only by visual inspection of welding sparks, shavings and simple flaring state, flattening test and other empirical methods of control, it is difficult to maintain a stable quality. 　　The shape and width of the weld affected zone are closely related to the welding speed, temperature, extrusion force and even tube thickness. When the welding speed constant, the heat affected zone width and welding temperature is proportional to (ie, the higher the temperature, the width of the larger), and inversely proportional to the extrusion force (ie, the greater the extrusion pressure, the smaller the width); when squeeze (Ie, the higher the temperature, the greater the widt...