LSAW Steel Pipe

　　Check and check the complete data of the stainless steel pipe. 　　We know that stainless steel seamless tube have high quality requirements for seamless pipes under high temperature and high pressure. 　　Cracks in the pipe, due to improper machining process during production, may lead to improper rolling or drawing die setting, folding, warping, scratching or strain, surface and internal defects, etc. In order to ensure the quality of seamless steel tubes , according to the relevant technical standards of the products, the seamless steel pipe production line requires surface and internal nondestructive testing. Commonly used eddy current testing and magnetic flux leakage detection technology. 　　Eddy current detection is an electromagnetic induction based on a nondestructive testing method. It drives a sinusoidal excitation probe coil, when the probe is close to the seamless surface, the induction current produced by the induction electromotive force, that is, the eddy in the alte...

　　Crevice corrosion is a form of local corrosion cracks when surface passivation layer of surface sediment or shielding area is destroyed. 　　There are cracks in the welding process or design of the stainless steel pipe joint at the other joint. In effective corrosion sites, the crack must be wide enough to allow corrosive electrolyte to enter the stagnant zone. The width of the corrosion crack is several meters wide, but it is not absolute. The critical crack size leads to corrosion. 　　In particular, the negative chlorine ions have high activity. Therefore, if there is an external body solution of the crack, the metal ions with positive charge are easily attracted to the narrow cracks. The cracks (usually chromium) in the metal chloride formed to form hydrochloric acid, reduce the pH value to passivate the pH value and passivate. The cracks in the membrane were destroyed and further pitted. Events should be passivated, corrosion will be fast and self - sustaining, especially when ...

　　The advantages of this ERW steel pipe processing technology are that there is a heat treatment process after welding to eliminate the residual stress in the weld and heat affected areas, to refine the grain, and to make the heat affected zone of the weld small, and the heating speed is fast, thus greatly improving the welding speed and welding quality, and can be used as a blank without pickling, shot peening and trimming. At the same time, it can weld alloy steel, high alloy steel and non-ferrous metal pipe, greatly reducing unit power consumption. A set of welding equipment can be used to produce each. 　　The advantages of this ERW steel tube processing technology are that there is a heat treatment process after welding to eliminate the residual stress in the weld and heat affected areas, to refine the grain, and to make the heat affected zone of the weld small, and the heating speed is fast, thus greatly improving the welding speed and welding quality, and can be used as a blank...

　　The polishing method of seamless steel pipe is as follows: 　　 1.mechanical polishing 　　The 1. advantage is that the parts are smooth and the brightness is high after processing. The disadvantage is that the labor intensity is too big, cause serious pollution, can not process complex parts, the luster can not be consistent, the heat preservation time is not long, the mechanical polishing is suitable for the processing simple parts, and the small and medium parts. 　 　2. chemical polishing 　　A little bit is investment equipment, complex parts can be polished, fast, efficient, good corrosion resistance, the drawback is poor lighting, ventilation equipment, heating difficulties. It is applicable to small complex parts and small parts that do not require high brightness. 　　 3. electrochemical polishing 　　The advantages are long mirror gloss, stable process, low cost and poor corrosion resistance. The disadvantage is that the equipment must be invested at a large time, the compl...

　　A spiral welded steel pipe is a steel pipe which is welded and formed by a steel strip or a steel plate to be deformed into a circular shape or a square shape and has a joint on the surface. According to different welding methods, it can be divided into arc welded pipe, high frequency or low frequency electric resistance welded pipe, gas welded pipe, furnace welded pipe, Bondi pipe and so on. According to the shape of the weld, it can be divided into a straight welded pipe and a spiral welded pipe. Electric welded steel pipes are used in oil drilling and machinery manufacturing. The furnace welded pipe can be used as a water gas pipe, etc., the large diameter straight seam welded pipe is used for high pressure oil and gas transportation, etc.; the spiral welded pipe is used for oil and gas transportation, pipe piles, piers and the like. 　　Welded steel pipes have lower cost and higher production efficiency than seamless steel pipes. Straight seam welded pipe has simple production pr...

　　The seamless expansion of the seamless steel tube is divided into an overall thermal expansion treatment, a surface thermal expansion treatment, and a chemical heat treatment. The seamless expansion of the seamless steel pipe is generally treated by integral thermal expansion. Generally, they are subjected to basic processes such as heating, heat preservation, and cooling, and defects may occur in these processes. 　　Heat treatment defects of seamless steel tubes mainly include unqualified structural properties of steel pipes, excessive size and surface cracks, scratches, severe oxidation, decarburization, overheating, and over-burning. 　　Features of thermal expansion processing of seamless steel tubes: 　　The first process is heating: one is heating below the critical point Ac1 or Ac3; the other is heating above the critical point Ac1 or Ac3. The first is mainly to stabilize the structure of the seamless steel pipe and to eliminate the residual stress of the seamless steel pipe,...

　　Common processing methods for steel pipe: 　　1. Forging method: use forging machine extend to the end or part of the tube, to reduce the outer diameter, commonly used forging machine are rotary, connecting rod, roller type. 　　2. Stamping method: use a tapered core on the punch to extend the pipe end to the desired size and shape. 　　3. Roller method: place the core in the tube,rolling the outer with a roller, used for the round edge processing. 　　4. Rolling method: generally it do not have mandrel, suitable for thick-walled tube with the round edge inside. 　　5. Bending method: There are three common methods: extension method, stamping method, roller method. There are three-four rollers, two fixed roller, a adjustment roller, adjust fixed roller distance, then finished pipe is bent. 　　6. Blowing method: one is placed in the tube rubber, the top with a punch compression, protruding shape the tube; another method is the hydraulic bulging shape, fill liquid in the middle of the...

　　1, High-quality seamless pipes of uniform composition, high cold shear tonnage, smooth and neat end face of the cutting head, and inferior materials due to the poor material, cut the first end surface there are often off the meat of the phenomenon that is uneven, and no metallic luster. And because of inferior materials manufacturers cutting products less head, head and tail will be a big ears. 　　2, Inferior seamless pipes without metallic luster, pale red or similar color of pig iron, there are two reasons for it blank is adobe. Inferior-rolling temperature is not standard, they are visually steel temperature, so can not be carried out according to the provisions of the austenitic region of rolling, thick-walled seamless performance naturally can not be reached. 　　3, Thick-walled seamless Inferior material containing impurities, the density of steel is small, and size tolerance serious, so without a vernier caliper case, you can check it weighed. 　　4, Thick-walled seamless pi...

　　In recent years, structure tubes is not only widely used in marine engineering and bridge engineering, but also widely used in industrial and civil construction. 　　More and more structure tubes used in China's building, In the use of square tube truss, Jilin skating Rink, Harbin Ice and Snow Exhibition Hall, Shanghai "Oriental Pearl" TV Tower and Changchun Nanling Gymnasium are using square steel pipe as the main structural components. 　　In the field of public buildings, some application of structure tube is unique, such as the Sydney Aquatic Centre, the United States Jarden Grove Crystal Church; single-storey space construction, except widely used in supermarkets, warehouses, there are also a number of very large structures, such as the Singapore Zhanghou Airport Hangar, the Osaka International Airport Terminal; in addition, there are also light large span structures such as pedestrian bridges and crane structures; other special usage of structure tubes can be ant...

　　ASTM A179 cold drawn seamless carbon steel pipe is mainly used in various sectors of the metal structure facilities, mainly after the rust of steel pieces immersed in 440 ~ 460 ℃ melting zinc solution, so that the steel surface attached to the zinc layer, which play a preservative purpose. This is an effective way of metal corrosion, the use of the main features are the following: 　　1. ASTM A179 cold drawn seamless pipe manufacturers with thick dense dense zinc layer covered in the cold drawn seamless tube surface, it can avoid cold drawn seamless tube matrix and any contact with the corrosion solution to protect the steel matrix from corrosion. In the general atmosphere, the surface of the zinc layer to form a layer of thin and dense zinc oxide surface, it is difficult to dissolve in water, so the steel matrix plays a protective role. If zinc oxide and other components of the atmosphere produce insoluble zinc salt, the anti-corrosion effect is more desirable. 　　2. With iron - z...

　　Cold rolled precision seamless steel tube (GB3639-2000) is a kind of seamless steel tube used for precision mechanical structure, hydraulic equipment and the steel sleeve with high precision and good surface. 　　High precision cold drawn precision steel tube is a new type of steel varieties, and its main characteristic is high precision. There are usually two kinds of production process including two roll mill and three roll mill production, the precision of the three roll mill production of cold rolled seamless steel tube is higher, but the price is relatively a few higher. 　　 Characteristics 　　Application of high precision cold drawn precision steel tube saves steel, improve processing efficiency with energy saving. High precision cold drawn seamless steel tube has inner and outer diameter size accuracy (tolerances) strictly, both inside and outside surface roughness, roundness, good straight degree and can greatly save the machining time, improve material utilization, at the ...

　　Finishing tube is also called cold rolled precision tube, it is one of the types of seamless steel tube production process. The characteristics of the fine rolling tube: 　　1. The cold rolled precision tube tolerance dimension precision is high, the product accuracy control in the plus or minus 5 mm, inside and outside wall finish good, surface oxide layer. 　　2. The comprehensive performance of cold rolled precision tube is good, can bear high pressure, cold bending, flaring, flattening not crack, not wrinkled skin, can do all kinds of complex deformation and mechanical processing. 　　3. The popularization and application of precision seamless steel pipe steel can save and improve processing efficiency and reduce machining process and equipment investment, can save cost and save machining time, greatly improve the production capacity and material utilization, at the same time to improve product quality, reduce the cost. 　　 Finishing pipe application: 　　Cold rolled precision ...

　　 Corrosion Protection 　　Coating or cathodic protection is not required for stainless steel in most locations. A thin chromium-rich self-healing oxide film provides corrosion protection for stainless steel and no corrosion allowance is required. Erosion Resistance Stainless steels are much more resistant to erosion-corrosion caused by high flow rates and particulate matter than steel. They can handle high velocity and turbulence (pumps) without suffering wall thickness erosion. 　　Low Coefficient of Friction 　　Stainless steel retains low hydraulic friction properties as compared to aging cement lined or corroded steel pipes, which results in lower water pressure losses and pumping cost savings. 　　 Ease of Fabrication 　　Stainless steels have excellent ductility and can be formed and welded into lightweight shapes, which assists in the handling and installation of pipelines. Stainless steel pipe is highly interchangeable and easily connected with other water piping systems and...