SSAW Pipe

　　There are many types of defects that may occur in the manufacturing process of seamless steel pipe. Depending on the production process, the types of defects also show differences. It is precisely because of these potential defects that the pipeline is greatly reduced in strength and premature failure during use, and even causes unpredictable losses. Therefore, taking effective measures to monitor defects in the production process in real time and identify the types of defects has far-reaching significance for improving product quality, improving processes, and rationally utilizing resources. 　　For a very large number of seamless steel pipe production lines, relying on manual intervention to identify the type of defects is obviously not in line with the requirements of modern mass production. In order to realize online automatic detection of defect type identification, many artificial intelligence algorithms show strong vitality in today's manufacturing informationization, such...

　　Boiler steel pipes includes medium pressure boiler pipe and high pressure boiler pipe, it is often manufactured in seamless procedures, welded steel pipe is not applicable. It has been widely used at heat exchanger pipe and tubing services, tube exchanger bundle, high pressure boiler, economizer, super heater, petrochemical industry pipes, etc. 　　Based on different working temperature, the medium or high pressure boiler pipe shall be used. Normally classified as below cases: 　　1. The operation temperature of general boiler pipe is lower than 450℃. The medium pressure boiler pipeline mainly adopts hot rolling process or cold drawing process. 　　2. High pressure boiler pipes are often used in high temperature and high pressure conditions. Under the action of high temperature flue gas and steam, the pipe will occur oxidation and corrosion. It is required high pressure boiler pipe that has high durable strength, high oxidation corrosion resistance and good tissue stability.

　　The method for quality inspection of LSAW pipe , in which the physical method is the most commonly used inspection method, physical examination is a physical phenomenon to determine or check the application of the method. 　　 Magnetic force 　　Magnetic flaw detection can only find the shortcomings of the appearance and appearance of the magnetic straight seam welded pipe. The disadvantages can only be quantitatively analyzed. The nature and depth of the flaw can only be estimated based on experience. Magnetic flaw detection is the use of magnetic field to discover the leakage of magnetic longitudinal weld seams. According to the method of measuring magnetic flux leakage, it can be divided into magnetic powder method, magnetic induction method and magnetic recording method, in which the magnetic powder method is the most widely used. 　　Soak inspection 　　Penetration testing is the use of some liquid physical properties such as permeability to detect and display defects, including...

　　 SSAW steel pipe is the steel pipe with spiral seam that using strip coil as raw material, extrusion forming under normal temperature, and welding by automatic Double wire double-sided submerged arc welding process. Classification of SSAW steel pipe includes: 　　1. SSAW steel pipe (SY5036-83) used for pressurized fluid transportation is mainly used for conveying oil and natural gas pipeline. 　　2. SSAW steel pipe (SY5038-83) used for pressurized fluid transportation, it is welded with high-frequency welding method. The loading capacity of it is powerful, the plastic is good, and it is easy to weld and machine shaping. 　　3. SSAW steel pipe (SY5037-83) used for general low-pressure fluid transmission, it is welded with double-sided automatic submerged arc welding method or one-side welding method, it is mainly used for water, gas, air and steam and other general low-pressure fluid delivery. 　　Now general standards for SSAW steel pipe is generally divided into: SY/T5037-2000 (min...

　　The magnitude of the tissue stress is related to the cooling rate, shape, and chemical composition of the workpiece in the martensitic transformation zone. The faster the cooling rate, the higher the carbon content and alloy composition, the greater the uneven plastic deformation caused by thermal stress during cooling, and the greater the residual stress formed. 　　On the other hand, in the process of heat treatment, when steel changes to austenite to martensite, the increase of specific volume is accompanied by the expansion of the volume of the workpiece, and the parts of the workpiece are successively transformed, resulting in inconsistent volume growth and tissue formation. stress. The final result of the change in tissue stress is the tensile stress on the surface layer and the compressive stress on the core, just opposite to the thermal stress. 　　When the large-diameter straight-welded welded pipe is finished at the end of cooling, the core portion of the surface is not pul...

　　Spiral welded steel pipes are widely used in oil, natural gas, water and other flammable & nonflammable liquid conveyance and distribution pipelines, steel structures for construction and other general purposes by means of their wide size range. 　　a. Molding process, the steel deformed uniformly, spiral steel pipe , residual stress, the surface does not produce scratches.Spiral steel pipe processing diameter and wall thickness in the range of sizes for greater flexibility, especially in the production of high grade thick-walled pipe, spiral steel pipe, especially small and medium-diameter thick-walled tube has advantages over other processes,to meet user specifications in steel demand more. 　　b. The use of advanced double-sided submerged arc welding process, welding can be achieved in the best position, less prone to the wrong side, partial and incomplete penetration welding defects, easy to control weld quality. 　　c. 100% of the steel quality inspection, so that the whole ...

　　The total zinc coating condition applied depends mainly on the mass and thickness of the galvanized steel tubing. Usually the surface of the galvanized layer should be complete and uniform and with a standard thickness. The evaluation of the appearance quality of the galvanized layer is very important. The following listed the common surface conditions of the galvanizing layer for galvanized steel pipe . 　 　1. Gray and dark-gray cobwebbing 　　The chemical elements of the steel tube such as C, Si, P and Mn will cause Fe-Zn alloy reaction with the increase of the content, produced zinc-iron alloy layer on the coating surface, especially with Si increased, which accelerate the reaction of iron-zinc melt mutually, formed on the surface of gray even the black net. The black coating layer is thicker than the bright coating, the corrosion protection and prevention ability completely inferior to the bright coating, but will be more resistant to corrosion but may not pretty sensually. Hot-...

　　The advantages of cold drawn steel tube 　　(1) the size is accuracy, tolerance is small; 　　(2) when the die hole machining is excellent, well-oiled and the surface of good quality and finish of up to seven; 　　(3) using it to produce small-diameter steel pipe and a special section; 　　(4) cold contribute to grain refinement of metals, together with the appropriate heat treatment to obtain good mechanical properties of steel pipe; 　　(5) The equipment is simple, flexible production methods, and to facilitate the replacement of species. 　　In addition, forming speed high yield without damage coating made various section forms meet the use conditions; cold rolled Steel great plastic deformation improve steel yield points.

　　 Spiral pipe is a very widely used pipe, sometimes it may require welding, but spiral pipe exsit welding defects. 　　Under normal circumstances, weld defects of spiral pipe has porosity, undercut and crack phenomena. 　　Helical tube bubble defects: conducting spiral welded, in the center of the weld bead, there will be the situation of bubble defects, will produce this situation? Main reason is that, in the welding process is hydrogen bubbles form of residue inside the metal. How to solve this failure? Welding process, we need to clear weld the inside of the oil, water and other ingredients, but also need good drying and removing moisture, so that hydrogen does not remain inside the weld . Increasing the welding current in the welding process and the generation of the bubble can be avoided yet. 　　Spiral undercut: v-shaped groove weld edge, and along the weld centerline, said undercut. Usually undercut is inappropriate because of the current, voltage and welding speed, therefore,...

　　What kind of demands would be here if a seamless steel pipe or ERW steel pipe produced in general automatic rolling machine? Today, we can have see the magic power together. 　　First of all, deviation on steel pipe’s diameter. The steel pipe’s bending in any part would be ≤6mm / m, the end face of the cut slope would be ≤6 ~ 8mm, and flattened pipe end face of ≤8%. 　　Secondly, if you want the steel pipe’s surface has no cracks, scarring, hairline and other defects. You need to know that the height or depth of the steel pipe is not more than 0.5mm small grooves, pitting, ears and height of more than two-sided ears of 1mm. 　　What’s more, for the low magnification steel pipe, we should make sure that there is no allowed for the residual shrinkage ≥1 level. And so many factors we need to focus on during the whole production process. 　　 http://www.xysteelpipe.com/info/Automatic-rolling-mill-production-of-steel-pipe-requirements-1253-1.htm