ERW Steel Pipe

　　 SSAW steel pipe often there will be some quality problems in the production and use, affecting normal use in some aspects, the need for spiral welded pipe to identify the quality, according to a certain way and performance testing, can produce significant in actual use role, then how to identify counterfeit spiral welded pipe method: the appearance often pockmarked face phenomenon. 　　Generally the whole proportionate amount would be better, mainly taking into account the cumulative error and probability theory this problem. Some of the above please add if inadequate, we welcome the discussion of knowledge about aspects of the steel pipe together, advances constantly exchange. Pock is due to badly worn groove spiral welded pipe surface irregularities caused by uneven defects. Because of shoddy spiral welded pipe manufacturers have to pursue profits, rolling groove most often exceeded. The surface is easy to produce scarring. 　　Quality spiral welded pipe of uniform composition. H...

　　 Spiral pipe factory should be done before the mechanical performance test and flattening test, and flaring test, and to achieve the standard requirements. Spiral steel pipe quality inspection method is as follows: 　　1, From the face of it, that is visual inspection. Visual inspection of welded joints is a simple procedure but widely used test method is an important part of product testing, the main defects and deviations are found on the surface of the weld size. Usually by the naked eye, with the standard model, gauge and test tools such as a magnifying glass. If the weld surface defects, weld defects there may be internal. 　　2, Physical test methods: physical test method is to use some physical phenomena assay or test method. Or within the workpiece material defect inspection, and are generally used NDT methods. NDT ultrasonic flaw detection, radiation detection, penetration testing, magnetic testing and so on. 　　3, Pressure vessels strength test: pressure vessels, in addit...

　　The casing pipe is a high-end product for steel pipe production. There are many types of casing, and there are a total of 15 types of casing diameter specifications. The outer diameter range is 114.3-508mm; the steel grade is divided into J55, K55, N80, L-80 , P-110, C-90, C-95, T-95 and other 11 kinds; casing pipe end buckle type and many types of requirements, can be processed button type STC, LC, BC, VAM and other buckle type. The casing pipe production and installation process involves a lot of tests, mainly the following: 　　 1, Ultrasonic testing 　　When the ultrasonic wave propagates in the material to be detected, the acoustic characteristics of the material and the changes in the internal structure have an influence on the propagation of the ultrasonic wave. Through the degree and condition of the ultrasonic wave to detect, to understand the change of the material properties and the structure. 　　 2. Ray detection 　　Radiographic examination uses the difference in the am...

　　The quality of tube billet is the main factor to judge the quality of seamless pipe. In order to ensure the reasonable progress of the perforating process and obtain high quality seamless steel tubes, it is necessary to make strict requirements for the geometrical size of the tube, the microstructure and the low magnification of the surface. 　　Seamless steel pipe 　　Too large diameter or too large oval shape will make the condition of perforation worse. At the same time, it will cause compression deformation due to the large diameter. 　　The key internal organizations are shrinkage and central porosity, non-metallic inclusions, and gas accumulation. The strictness of this requirement varies with the use of seamless steel tubes and steel grades. 　　The most important thing is the surface quality of the tube, because in the steel tube billet to any disabled city seamless tube product, often misplaced sites lead to stress concentration, plastic deformation will deepen and extend th...

　　LSAW pipe fracture, hydraulic (pneumatic) parts in mechanical performance design, brittle fracture is also related to the temperature of parts. 　　It is found that when the temperature is lower than a certain temperature, the data will change to brittle state and the impact absorption power will decrease obviously. This phenomenon is called low stress brittle fracture in this process. In cold brittle and high strength metal materials, there are cracks in non-uniform isotropic tissue in the data organization, as well as inclusions and pores. All these defects can be regarded as micro cracks in materials. Therefore, the design time should be selected according to the components of the working temperature to select the appropriate cold brittle transition temperature data. 　 　LSAW pipeline 　　It is generally considered that the data are homogeneous, continuous and isotropic. According to this analysis method, it is considered safety design, and sometimes it will crack unexpectedly. ...

　　OCTG is a kind of high-level product made of steel pipes. For OCTG’s diameter, there are 15 kinds. For OCTG’s steel grade, there are 11 kinds, such as J55, K55, etc. For it’s pipe end treatment, there are also many kinds, such as VAM, TOP VAM, LC, BC, STC, etc. As OCTG is quite a delicate steel pipe, so how much do you know about the testing method s of OCTG? Here we will introduce you some test methods of OCTG: 　 　1. Eddy Current Testing 　　Eddy current testing mainly uses the eddies in the work piece produced by magnet coils to analyze the internal qualities of the work pieces, and to detect the surface and near surface defects of various kinds of conductive materials. 　　 2. Ultrasonic Testing 　　When ultrasonic waves propagate in the tested material, acoustic characteristics of the material and changes of internal structures have a certain influence on the propagation of ultrasonic waves. We can know the changes of material's performance and structure by the influence de...

　　The heat treatment of 15CrMo seamless steel pipe is one of important process in manufacturing process. 　　Compared with other processes, the heat treatment generally does not change the shape and chemical compositions of 15CrMo seamless steel pipe. It changes the chemical composition of the surface of 15CrMo seamless steel pipe, to improve the performance of the workpiece. In order to make the 15CrMo seamless steel pipe has the required mechanical properties, physical properties and chemical properties, heat treatment is necessary besides selecting reasonable materials and a variety of forming process. 　　Steel is the most widely used material in the mechanical industry. In the 1960s, the heat treatment takes advantage of plasma field which make 15CrMo seamless steel pipe obtain new technology for surface heat treatment and chemical heat treatment. Heat treatment can control the microstructure of steel, therefore, heat treatment is important for 15CrMo seamless steel pipe. 　　 htt...

　　Seamless elbow is manufactured by the seamless steel pipe, through hot push, press or extrusion processes, no seam on the elbow body. 　　Welded elbow is manufactured by welded steel pipe, same processes with seamless elbow.But there is a seam on the elbow body. 　　Prime steel pipe tells you the differences between seamless elbow and welded elbow on raw material, manufacturing processes, performances, appearances, sizes, applications, cost prices etc. 　　 1. Appearance difference 　　The biggest difference between seamless elbows and welded elbows are whether there is a weld, but now many of the welded steel pipes will be polished off the welding seam before they leave the factory. The elbow that is made out of this steel pipe is invisible to the welding seam.There are a lot of exporter sell this kind of fake seamless elbow to customers. This kind of elbow is difficult to distinguish with the naked eye, and it needs to use professional testing tools. For now,false seamless elbow of...

　　 ERW carbon steel tube vs spiral pipe: 　　First, the difference between the production process 　　ERW carbon steel pipe is the hot rolled coil through the continuous roll forming, the use of high-frequency current skin effect and proximity effects, so that the edge of the coil heat fusion, pressure in the squeeze roller under pressure welding to achieve production. Therefore, erw carbon steel pipe residual stress is small, through the weld heat treatment, sizing, straightening, water pressure and other processes, the residual stress to further release and reduce. Practice has proved that erw carbon steel pipe in the storage and use of residual stress on the steel pipe does not affect. Without any welding wire, the weld in the physical properties and chemical composition with the plate exactly the same. The quality of the erw carbon steel pipe depends on the quality of the sheet. 　　Second, the difference between raw materials 3, ERW carbon steel pipe within the weld is relatively ...

　　The main factors that affect the quality of seamless steel tube machining are machine tools, knives, fixtures, workpiece blanks, process methods and processing environment. To improve the quality of seamless steel tube cutting, we must take appropriate measures in these areas, such as reducing machine work error, the correct selection of cutting tools to improve the quality of blanks, reasonable arrangements for the process to improve environmental conditions. 　　Commonly used methods to reduce the cutting error of seamless machine tools are: 　　(1) enough precision and stiffness of the machine. 　　(2) if necessary, it is possible to use the revise method of screw grinder or hobbing machine to correct the error of the machine tool transmission system according to the previously measured machine chain error correction device. 　　(3) Use the machine tool jig to ensure the machining precision, for example, using the drill die processing box on the drilling system, so that the precis...

    Gi seamless pipe during the welding process of the fluid pipe, due to various reasons, there may be some hidden dangers. Therefore, regular safety inspections are necessary. Below, let me introduce the precautions for welding safety inspection.     Welding site, equipment safety inspection:     1. Check whether the equipment, tools, and materials for the welding and cutting work points are arranged neatly and not in a random manner.     2. Check whether the welding site maintains the necessary channels, and the width of the vehicle channel is not less than 3m, and the pedestrian channel is not less than 1.5m.     3. Check whether all welding hoses and welding cables are entangled with each other. If they are entangled, they must be separated. Whether the cylinders are removed from the work site after use or not, various gas cylinders at the work site must not be placed horizontally.     4. Check whether the weldin...

    In both low and high pressure environment, we should obtain the legal steel pipe from seamless steel tube, ERW steel pipe and SSAW steel pipe for long-term life service.Under this situation, we should figure out the characters and main application environment for different steel pipes. Today, we would have an introduction for application range for high frequency longitudinal ERW steel pipe.     1. Oil, natural gas convey: Municipal gas transmission, long distance transportation of oil and natural gas would under the help of high frequency longitudinal ERW steel pipe.     2. Casing and tubing: This is another area we can count on ERW steel pipe. There is only seamless steel pipe can hold on this duty. However, with the high technology's development, now we can use ERW steel pipe to replace it.     3. Constructional structural pipes: No matter round, square or rectangular, we can use ERW steel pipe for frameworks of super malls, theater, a...

    The solution temperature is mainly determined by chemical composition. In general, the solution temperature should increase for those containing many kinds of alloy elements or with high alloy. Especially for those that contains high steel, like manganese, molybdenum, nickel, silicon. Only by increasing the solution temperature can we dissolve and soften them. But for stabilized steels such as 321 stainless steel pipe, when the solution temperature is high, the carbide of the stabilizing elements are fully dissolved in the austenite and precipitate in the grain boundary with the form of Cr23C6 after cooling. That can cause intergranular corrosion. We often adopt the lowest solution temperature for carbide(Tic and NbC) of the stabilizing elements which can't be dissolved or treated by solid solution.     For seamless stainless steel pipe, the three elements of the solution treatment are temperature, holding time and cooling rate. What is the role of solution tre...

    Precision Seamless Steel Tube Pickling Overview:     The use of an acid solution to remove scale and rust from steel surfaces is called pickling. Iron oxides (Fe3O4, Fe2O3, FeO, etc.), such as scales and rust, chemically react with the acid solution to form salts that are dissolved in the acid solution and removed. Pickling acids include sulfuric acid, hydrochloric acid, phosphoric acid, nitric acid, and mixed acids.     Precise seamless steel pipe pickling commonly used media: sulfuric acid, nitric acid, phosphoric acid, hydrofluoric acid. Be sure to add pickling inhibitors during pickling to prevent acid corrosion of metals.     Precision seamless steel pipe pickling process     Mainly impregnated pickling, jet pickling and acid paste rust removal. In general, the impregnation pickling method is generally used, and the spray method can be used in mass production. Steel parts are generally pickled in 10% to 20% (by volume) s...

    First, the relationship between hardness and tensile strength     When the hardness of the steel is below 500 HB, the tensile strength is proportional to the hardness, kg/mm2(óB)=1/3 X HB=3.2 X HRC=2.1 X HS, but the above relation is not in any case. Established, from the aspect of heat treatment, when the tempering temperature is low, the correlation between kg/mm2 and HRC may be destroyed. The relationship between the tempering temperature, hardness and tensile strength of steel is shown in the figure.     From this figure, it can be seen that the hardness decreases with the increase of the tempering temperature, but the relationship between the hardness and the tensile strength cannot be established when the steel is quenched and tempered at a temperature of 300° C. or lower. When the tempering temperature is around 300°C, there is a correlation between kg/mm2 and HRC, that is, the hardness is high, the tensile strength is high, the hardness is l...