ERW Steel Pipe

　　The classification of seamless steel pipe is hot rolled and cold drawn seamless steel pipe. 　　 Disadvantages of seamless steel pipe: 　　1. After this hot rolling, the steel inside the non-metallic inclusions (mainly sulphide and oxide, and silicates) is pressed into the sheet, delamination (interlayer) phenomenon. Hierarchical position of the steel in the thickness tensile performance deteriorated significantly, and there can be positive which is torn between layers of weld shrinkage occurs. Weld heavily strain-induced contraction of the yield point strain often arrive several times larger than the load-induced strain; 　　2. uneven cooling constitute surplus stress. Stress is stress positive surplus is no external force equilibrium of internal self-rolled steel sections have such a surplus of various stress, the greater the deformity steel sectional dimensions, the greater the stress surplus. Although earnings from stress equilibrium, but the performance on the steel members are...

　　Causes of uneven thick cold drawn seamless steel : 　　1) Cut the tube front slope, bending through the large, tube-centering holes errors could easily lead to uneven wall thickness of the head pipe. 　　2) When the perforation extension coefficient is too large, roll speed is too high, rolling instability. 　　3) puncher throwing steel capillary instability could easily lead to the tail of uneven thickness. 　　Cold drawn seamless steel thick uneven measures 　　1) Check the quality of the tube to prevent the tube front cut slope, volume reduction, replacement or repair should be corrected pass-centering holes. 　　2) a lower rate of perforations to ensure the stability and uniformity of the wall thickness of the rolled hair. When the roll speed adjustment, matching the guide plate is also adjusted accordingly. 　　3) the use of state concern and guide disc guide plate bolts to increase inspection efforts to reduce lead in the rolled steel plate ran magnitude, throwing steel to ensu...

　　Pipeline transportation is developed along with the increase in oil and natural gas production. It is a transportation technology that uses gas to deliver gas, liquid and fluid. At present, it has become the main mode of transportation for onshore oil, gas and granular coal transportation. In recent years, the pipelines for conveying solid materials are mainly seamless steel pipes, and fluids are often used for casings pipes. The pipelines also have great development in the transportation of granular coal and concentrates; 　　First, the advantages： 　　(1) It can be transported continuously, is not affected by the weather, and has high reliability throughout the day. 　　(2) The pipeline can take shortcuts and the transportation distance is short; 　　(3) The transportation volume is large. A foreign coal pipe with a diameter of 720 mm can transport 20 million tons of coal a year, which is almost equivalent to the single-direction conveying capacity of a single-track railway; 　　(4...

　　Cold drawn steel pipe is normally divided into low and medium pressure boiler pipe, high pressure boiler pipe, steel pipe, stainless steel pipe, oil cracking pipe, the other steel, but also thin-walled carbon steel, alloy steel thin-walled, thin-walled stainless steel, special steel pipe. 　　Cold drawn means at room temperature, after cold drawing, cold, cold drawn, such as the processing of cold steel or steel into various types steel. (including a tapered pipe, oval shaped steel pipe, etc. are manufactured using this method) 　　Advantages of cold drawn steel pipe: molding speed, high output, and does not damage the coating, can be in the form of cutting brittle various kinds of cross section, to meet the needs of the conditions of use. Cold drawn can make the steel produces very large plastic deformation, thus improve the yield point of steel. 　 　Disadvantages of cold drawn steel pipe: 　　1. Although the molding process is without thermal plastic compression, but there are sti...

　　Due to restrictions by its production process, seamless steel pipe production costs have been high, resulting in the gradual decline of its economic benefits. As technology advances China's metallurgical industry, new products instead of seamless steel pipe hot stretch reducing began to emerge. 　　1, the quality directly determines the quality of the weld pipes, ERW and seamless pipes is also the biggest difference lies. Longitudinal after the high-frequency welding, seam straight sets carbon can not be eliminated, but the weld interface together with the parent, and not completely fused into one, could not stand the test of time and pressure. Reducing the overall thermal tension in the high-frequency welded steel pipes go through a heating temperature of 800 degrees, the overall annealing, and then open the transformation treatment, after this series of processes, the weld and the parent organization has the same performance, fully fused into one , well done from a seam to a s...

　　The first one is flux-cored wires. When welding out of position on thick-walled welded steel pipe , it is better to choose gas-shielded flux-cored wire to achieve high deposition rates. This kind of filler metal can weld out of position without a special power, and the flux coating on the wire can be considered as a dam which can hold the molten weld pool in place. Therefore, the flux –cored wires are useful for improving productivity. However, there are some disadvantages when using the flux-cored wires in the welded steel pipe. Higher levels of smoke may be produced and a slag may be generated by the wires. Then both between passes and after the cap pass, the welding operators will need to chip or grind in, which in turn leads to greater downtime for cleanup. 　　The other kind is metal-cored wires. When welding welded steel pipe, the metal-cored wires are accepted more and more widely. The available diameters of the metal-cored wires range from 0.035- to 1/16-inch. In order to wel...

　　As the name implies, the main constituents of welded steel pipe is steel and carbon. Because of to the composition of these pipes, they are nicely suited for commercial and geothermal applications due to the reality of the tensile power they offer. These pipes are seamless and for that reason confirm to be of outstanding electricity as essential oil pipelines or as transporters of other fluids. The broad distribute utilization of the seamless carbon steel pipes is due to the reality of the composition and the advantages that they offer. These pipes are an apparent selection for heavy requirement commercial performs due to the tensile power of these pipes. Be it the making or mammoth ships, or even the performing elements of massive machinery, these pipes endure the stress nicely sufficient to invoke self-confidence in its end users. 　　When security and durability are of concern, these welded steel pipes pass the check with elan. The carbon steel pipes are resistant to vibration, s...

　　In the production process of steel pipes, whether it is a seamless pipe or a casing pipe, it is often necessary to measure the degree of completion of the processing of the steel pipe and the adjustment of the process and the adjustment of the heat treatment by measuring the hardness of the steel pipe, so that the performance of the steel pipe meets the requirements of the customer. index of. The hardness of seamless steel tubes is generally measured by three hardness indexes: Brinell, Rockwell and Vickers. Today we will talk about the hardness measurement of steel pipes. 　　In the steel pipe standard, the Brinell hardness of the steel pipe is the most widely used, and the hardness of the material is often expressed by the indentation diameter, which is intuitive and convenient. However, it is not suitable for hard or thin steel pipes. 　　The Rockwell hardness test of steel pipes is the same as the Brinell hardness test. The difference is that it measures the depth of the indentati...

　　The process on manufacturing welded steel pipe is complicated. Starting from the steel billet with solid and round feature, then turn to increase the temperature and make it flexible until we can hollow this billet into a tube. We have to admit that the process will cost you lots of money and time, but at the same time the quality is satisfied. As you may have already known that, there are lots of benefits of welded steel pipe. 　 　Increased Pressure Ratings 　　The most impressive trait of it is their strength to endure pressure, while the disadvantage of seamless pipe is their seamless. Because the welded one has been welded and has that seam, which make it strong enough to bear the entire circumstance. What's more, it would be more likely to take pressure figure into account for the quality even sometimes without required. Although the welded pipe would be little expensive than the seamless ones once a while, this folding strength allows you to cut down your expenses since t...