steel pipe

　　GCr15 Pipe is a high carbon chromium bearing steel with less alloy content, good performance and wide application. After quenching and tempering, it has high and uniform hardness, good wear resistance and high contact fatigue performance. The cold working of the steel is medium in plasticity, the cutting performance is general, the welding performance is poor, the sensitivity to white spots is large, and the temper brittleness is obtained. 　　Chemical composition / element content (%) 　　C: 0.95-1.05 Mn: 0.20-0.40 Si: 0.15-0.35 S: <=0.020 P: <=0.027 Cr: 1.30-1.65 　　The heat treatment system is: steel bar annealing, annealing or oil quenching at 830-840 °C. 　　Heat treatment process parameters: 　　1. Ordinary annealing: heating at 790-810 °C, after the furnace is cooled to 650 °C, air cooling - HB170-207 　　2. Isothermal annealing: 790-810 ° C heating, 710-720 ° C isothermal, air cooling - HB207-229 　　3. Normal fire: 900-920 ° C heating, air cooling - HB270-390 　　4. H...

　　When brown rust appeared on the surface of stainless steel , people were amazed: "Stainless steel will not rust, rust is not stainless steel, it may be a problem with steel." In fact, this is a one-sided misconception about the lack of understanding of stainless steel. Stainless steel will also rust under certain conditions. 　　Stainless steel has the ability to resist atmospheric oxidation, that is, rust, and also has the ability to resist corrosion in a medium containing acid, alkali, and salt, that is, corrosion resistance. However, the amount of corrosion resistance varies with the chemical composition of the steel itself, the state of each other, the conditions of use, and the type of environmental medium. For example, 304 material has absolutely excellent corrosion resistance in dry and clean atmosphere, but when it is moved to coastal areas, it will rust quickly in sea fog containing a lot of salt. Therefore, not any kind of stainless steel can resist corrosion and ...

　　The wall thickness is indicated by the pipe number "Sch". 　　Sch.20 ---- Full name: Schedule 20. 　　Sch.10s ---- The series with s is special for stainless steel, carbon steel is not used. 　　 For example: 　　2" sch.10s ---- indicates that the 2" pipe has a wall thickness of 2.9mm and is made of stainless steel. 　　2" sch.40 ---- indicates that the 2" pipe has a wall thickness of 4.0 mm. 　　The method for expressing the wall thickness of steel pipe has three methods: pipe gauge size, steel pipe wall thickness dimension and pipe weight. 　　1) The wall thickness is indicated by the pipe number "Sch". 　　The pipe number is the ratio of the pipe design pressure to the allowable stress of the material at the design temperature multiplied by 1000 and rounded. 　　Namely: Sch=P/[σ]t×1000 　　ANSI B36.10 wall thickness rating: Sch10, Sch20, Sch30, Sch40, Sch60, Sch80, Sch100, Sch120, Sch140, Sch160 ten grades. 　　ANSI B36.19 wall thickness gr...

　　Advantages of high frequency straight seam welded pipe 　　(1) High frequency straight seam welded pipe forming process is small rebound, the remaining stress is small. 　　(2) Deformation hardening effect is small, the whole circle after the geometric standard is accurate, conducive to ensuring the construction and welding quality. 　　(3) High frequency straight seam welded pipe weld shape is good, not prone to undercut, the surface welding is not a medium defect. 　　(4) High frequency straight seam welded pipe bead distribution in the circumference of a point, therefore, according to the requirements of the weld on the favorable position.

　　There are many types of spiral steel pipes produced by spiral steel pipe manufacturers. In the process of loading and unloading, it is inevitable that steel pipe damage will occur. For this situation, we have summarized a series of spiral steel pipe requirements and methods. The specific matters are as follows: 　　1. Spiral steel pipe packaging should be able to avoid looseness and damage during normal handling, transportation and storage. 　　2. If the buyer has special requirements on the packaging materials and packaging methods of the spiral steel pipe, it shall be indicated in the contract; if not specified, the packaging materials and packaging methods shall be selected by the supplier. 　　3. The packaging materials should comply with the relevant regulations. If packaging materials are not required, they should meet the intended use to avoid waste and cause environmental pollution. 　　4. If the customer requests that the spiral steel pipe cannot be damaged by bumps or the l...

　　1. Welded steel pipe (GB/T3092-1993) used in Low-pressure fluid delivery, also known as the general welded pipe, commonly known as black tube. It is the welded steel pipe that used to transport of water, gas, air, oil and heating steam, and other generally fluids with lower pressure. Steel pipe is divided into ordinary steel pipe and thickened pipe according wall thickness; is divided into non-threaded steel pipe (light pipe) and threaded steel pipe according to the form of pipe end. The specifications of the steel pipe are denoted by nominal caliber (mm), and the nominal caliber is the approximate value of the inner diameter. It traditionally uses inches to express, such as 11/2 and so on. Welded steel pipe used in Low-pressure fluid delivery in addition to directly use for the transport of fluid, but also is used as the original tube of galvanized welded steel pipe used in Low-pressure fluid delivery. 　　2. Galvanized welded steel pipe (GB/T3091-1993) used in Low-pressure fluid t...

　　Welded steel pipe, also known as welded pipe, is the steel pipe that made of steel plate or steel strip after crimped and welded. The production process of welded steel pipe is simple, production efficiency is high, variety specifications are many, the investment of equipment is little, but its general strength is lower than the seamless steel pipe. Since the 1930s, with the rapid development of high-quality strip continuous rolling line and the improvement of welding and inspection technology, the quality of welding line has been increasing continuously, and the specifications of welded steel pipes have been increasing. And welded pipe have replaced the seamless steel pipe in more and more field. Sewing steel pipe. The welded steel pipe is divided into straight seam welded pipe(also called LSAW steel pipe) and spiral welded pipe(also called SSAW steel pipe) according to the form of welding line. 　　Production process of LSAW steel pipe is simple, production efficiency is high, cos...

　　Welding quality of welded steel pipe refers to the degree to which the welding product meets the design technical requirements. Welding quality not only affects the use performance and life of welding products, more importantly, affects personal and property safety. Welding quality is usually ensured by design quality, processing quality, quality inspection and post-weld treatment and other links of the product. 　 　Design Quality 　　The type of joint used in the welding product and its calculated strength should meet the actual carrying capacity. Welding method should be suitable for the characteristics of components, and its economical efficiency should be good. The welding process should be able to minimize stress, deformation and stress concentration. Production labor and material consumption should be as small as possible, the convenience of flaw detection should also be taken into consideration when design the joint. 　 　Processing Quality 　　The performance of adopted the...

　　As there are sulfur and acidic substances on the transported oil, and pipes are exposed to the open air and suffer wind and rain, which causes the pipe to be easily corroded. 　　 Pipeline corrosion mainly contains several following ways, in which oxygen corrosion is the most corrosion. 　　1. Steel oxygen corrosion caused by the principle of the primary battery; 　　2. Hydrogen evolution corrosion caused by the surface of the acid sulfide (sulfur dioxide and hydrogen sulfide) caused by acid rain; 　　3. Carbon dioxide sour corrosion caused by atmospheric precipitation; 　　4. Bacterial corrosion caused by the germ that can metabolize the sulfate on the surface of the pipeline and the corrosion caused by the hydrops inner pipeline and so on. 　　As the causes and conditions of pipeline corrosion are not the same, the corrosion of the pipeline based on different corrosion also has the following different ways: 　　1. Reasonable choose a material, according to different transmission m...

　　Seamless pipe fittings elbow is the main connecting part of pressure pipeline. At present, the production of seamless elbow has cold push, hot push, stamping and other methods, and the cold push process still occupies an important position in elbow production. Although the cold push elbow has outstanding advantages, but the deformation law is more complicated and the process is difficult to control, it is very necessary to study the cold forming process of the elbow, improve the cold push elbow technology, and provide technology for the development of the elbow production process. stand by. 　　The simulation analysis of the cold push process of the elbow was carried out, and the results obtained by the finite element simulation were compared with the actual production. The reliability of the finite element simulation was confirmed, and the optimized tube blank size determination method was used to determine Φ273×8. The elbow blank size was optimized and the feasibility of using a re...

　　According to the production process, longitudinal steel pipes can be divided into high-frequency longitudinal steel pipes and submerged arc welded longitudinal steel pipes. Submerged arc welded straight seam steel pipes are further divided into UOE, RBE, JCOE steel pipes according to their different molding methods. The following describes the most common molding processes for high-frequency longitudinal steel tubes and submerged arc welded longitudinal steel tubes. 　　 Submerged arc welding process 　　1. Panel inspection: After the steel plate used to manufacture the large-diameter submerged arc welded longitudinal steel pipe enters the production line, the whole board ultrasonic inspection is first carried out. 　　2. Edge milling: double-sided milling the two edges of the steel plate by the edge milling machine to achieve the required plate width, parallelism of the edge and the shape of the groove. 　　3. Pre-bending edge: use the pre-bending machine to pre-bend the edge of the...

　　When the factories of Prime Steel Pipe manufacture welded steel pipe , the strip is fed into the welded pipe unit, rolled by the multi-way roll, the strip is gradually rolled up to form the circular tube with the opening gap, the pressing amount of the pressing roller is adjusted so that the gap of the weld is controlled at 1 ~ And make the ends of the weld flush. If the gap is too large, resulting in reduced proximity effect, insufficient eddy current heat, weld intergranular junction failure caused by non-fusion or cracking. If the gap is too small is caused by the adjacent effect increases, welding heat is too large, resulting in weld burns; or weld seam formed a deep pit after squeezing and rolling, which affects the surface quality of the weld. 　　1.The control of welding temperature 　　The welding temperature is mainly affected by the high-frequency eddy current thermal power. According to the correlation formula, the high-frequency eddy current heat is mainly affected by the...

　　Today, Prime Steel Pipe will share the type of rotary contact wheel welding for everyone. In rotary contact wheel welding, the electrical current is transmitted through a contact wheel at the weld point. The contact wheel also applies some of the forge pressure necessary for the welding process. The three main types of rotary contact wheel welders are AC, DC, and square wave. In all three power supplies, electrical current is transferred by brush assemblies that engage slip rings attached to a rotating shaft that supports the contact wheels. These contact wheels transfer the current to the strip edges. 　　AC Rotary Contact Wheel Welding. In an AC rotary contact wheel welding machine, the current is transferred through the brushes to the rotating shaft, which has a transformer mounted on it. The transformer reduces the voltage and increases the current, making it suitable for welding. The two legs of the transformer's output circuit are connected to the two halves of the rotating...

　　Double submerged arc welded spiral steel pipe is a kind of spiral welded pipe created by Prime Steel Pipe. With its high capability, tiny resistance, coldness resistance, corrosion resistance, straightforward installation and maintenance, etc., it's favored by a lot of and a lot of oil and gas, slurry transportation, urban construction and alternative industries. 　　The producing process of spiral double welding pipe: 　　1. Double submerged arc fastening method, the plate deformation uniformly tiny, residual stress, surface doesn't turn out scratches. process of pipe diameter and wall thickness of the pipe sizes range, larger flexibility, particularly within the production of top-grade steel thick-walled steel pipe, massive diameter thick wall pipe has the unparalleled advantage of alternative technology, to satisfy the users in pipe size requirements; 　　2. Bewildering outside fastening (the fine welding) the method are often enforced within the best position fastening, ...

　　Modern urban gas transmission and distribution system is a complex integrated facilities, the main part of it is the gas pipe network. The cost of the pipeline laying takes up about 60% to 70% of the total cost of the project, of which the cost of pipe takes up about 60% of the cost of laying the pipe network. There are many types of pipes used for conveying gas, mainly includes steel pipe, cast iron pipe and PE plastic pipe and so on. We must be based on the nature of the gas, system pressure and construction requirements to choose, and should meet the mechanical strength, corrosion resistance, seismic and air tightness and other basic requirements. 　　Steel pipe is the most widely used pipe in gas engineering. In the field of urban gas, and even the entire gas field, steel pipe has played an irreplaceable important role. Its main advantages are: high strength, good toughness, bearing stress, impact resistance and tightness, good plasticity, easy welding and hot processing, thin w...