SSAW Pipe

　　Domestic high-precision seamless steel pipes generally improve the properties of materials by adding alloys to metals. After cold drawing, seamless steel pipes need to be subjected to stress relief annealing to eliminate residual stress of materials, improve material structure and improve materials. Plasticity, so as to prevent the occurrence of fracture failure of seamless steel pipe. 　　At present, the material of China's stainless steel seamless steel pipe is ordinary 45# or 20# steel 27SiMn steel, which improves the strength of the metal by cold drawing deformation; however, it is at the expense of plasticity and toughness of the sacrificial metal. High-precision cold-drawn seamless steel pipe is based on its high dimensional accuracy and high strength performance. It must ensure that the deformation amount is within a certain range to maximize the performance of the material and reduce the material. Negative Effects. 　　The deformation of the seamless steel pipe is too sma...

　　In the construction and repair of gas pipeline welding operations, sometimes magnetic blow phenomena affect the welding process. 　　The formation of magnetic blow pipe metal present in remanence results. Typically, the remanence is divided into two kinds of induction magnetic and processes magnetic. Often produce magnetic induction pipe part in the factory, such as: metal smelting, using electromagnetic crane for loading and unloading, pipe parked in a strong magnetic field, the magnetization method with complete nondestructive inspection, pipe placed close to power lines and so powerful. Magnetic assembly processes often produce during welding operations and the use of a magnetic holder, clamps and pipe welding with DC, such as: prolonged contact with the DC power supply connected to electrical conductors, bare wire welding clamp and pipe segment or short-circuit and so on. 　　When the welding magnetic seamless steel tube, often can see the difficulties of arc ignition, arc burnin...

　　Thread pipe and spiral pipe are one of welded steel pipe , but both there are essential differences. 　　The form of thread pipe present in the tube end, the majority of the connection tube is used. Particularly in the pipe connections are optional steel pipe, which can be more secure. Thread pipe is not just used for pipe connections, can also be used for casing and tubing connections. Thread pipe has high thermal conductivity coefficient, internal heat required for the heat than the external high places. Thread pipe have improved the performance and can keep temperature at work, in particular, the internal temperature. Under normal circumstances the internal temperature of the steel tube a temperature is higher than the outside 1 times. 　　Spiral steel pipe external form is rolled steel plate, and in a more visible on the surface of the weld. Spiral pipe has a strong corrosion resistance, is not susceptible to corrosion, the use of relatively long duration. So strong resistance t...

　　Capillary rolling is the main deformation process of seamless steel tube.Its function is to make the wall thickness of the capillary close to or reach the thickness of the finished pipe wall, and eliminate the non-uniform wall thickness of the capillary in the perforation process.The surface quality of the internal and external parts of the waste pipe is controlled, and the outer diameter and roundness of the waste pipe are controlled. The hollow capillary is rolled into a waste pipe near the final size. 　　1, double roll mill: continuous rolling mill is a more advanced steel tube rolling mill. It puts the porous capillary on the long mandrel, which is arranged on a number of frames in turn, and the joint of the adjacent frame roll is 90 degrees. The continuous pipe mill is rolled. The main material of the continuous roll is Ni Cr Mo infinite cold hard ductile iron (also known as Pearlite Nodular Cast Iron), nickel molybdenum infinite cold hard ductile iron (also called acicular nod...

　　Except for trestle and steel scaffolding system divided according to original material. Today, we would category the scaffolding system into single and double one. The detailed introduction and difference for them. 　　Single scaffolding, generally speaking, would be used for brick masonry. Thus, it is also known as brick layer’s scaffolding. This kind of product corresponds to the wall at the distance of about 1.2 m. This would be determined by the structure. And distance, mostly, the standards is around 2 to 2.5 m. Ledgers join the standards at an upright gap of 1.2 to 1.5 m. 　　Double scaffolding would be functioned at stone masonry job. Thus, it can be called mason’s scaffolding. Typically, in stone walls, it is tough to make holes in the wall for supporting putlogs; thus, two scaffolding rows are made to make it robust. 　　Due to the difference of single and double scaffolding, customers would know how to choose the suitable one for their engineering project. 　　 http://www.x...

　　In the production process of erw steel pipe, when the roll is damaged or worn seriously, some rolls need to be replaced on the unit, or a certain quantity is continuously produced in sufficient quantity, and the entire set of rolls needs to be replaced. At this time, the rolls should be adjusted to obtain good steel pipe quality. If the roll is not well adjusted, it is easy to cause the torsion of the steel pipe joint, lap welding, edge wave, embossing and scratching on the surface of the drum and the pipe body, and the ovality of the steel pipe is large. Therefore, the roll adjustment should be mastered when changing the roll. skill. 　　1) Replace the steel pipe specifications, generally replace the entire set of rolls. The method of adjusting the roll is to use a steel wire to pull a center line from the inlet to the outlet of the unit, and make adjustment so that each hole type is on a center line, and the forming bottom line meets the technical requirements. After changing the s...

　　Main equipment of high frequency electrical resistance welded steel pipe production line are as follows: 　 　1, The uncoiler 　　The hot rolled steel strip is taken apart and sent to the strip leveler. It is divided into two types: unwinding and unwinding. The uncoiler is the line front end equipment of the high frequency welded pipe production line. 　 　2, Steel belt leveling machine 　　The strip is leveled before the welded pipe unit is formed. Generally, there are upper base, lower base, transmission device, etc., there are five rolls, seven rolls, etc. In the high frequency welded pipe production line, a pinch roll is usually arranged in front of the leveling machine. 　　3, Shear butt welding machine 　　In order to ensure the continuous production of the high-frequency welded pipe production line, it is necessary to cut the irregular ends of the front and rear strips by the shear butt welder, and clamp and weld them together to form a continuously produced strip. 　 　4, Sto...

　　LSAW steel pipes have several flaw detection tests. LSAW steel pipes are now used more and more widely. According to different projects, the standards for using steel pipes are also different. 　　Generally speaking, steel structures, piling, sewage discharge pipes, etc. There is no requirement for flaw detection of steel pipes, no need for flaw detection, and the projects used for flaw detection are: natural gas pipelines, oil pipelines, fire pipelines, etc. These projects have extremely strict requirements for flaw detection, and some strength flaw detection standards are related to The safety of the project is even related to the safety of people's lives. 　　There are two types of flaw detection that are most widely used. One is ultrasonic flaw detection. This type of flaw detection is to use ultrasonic energy to penetrate into the depth of the metal material and to reflect at the edge of the interface when one section enters another section. A method of part defect, when the...

　　The erw steel pipe production process requires a series of processes from raw materials to finished products. To complete these processes, various mechanical equipments and welding, electrical control and testing devices are required. These devices and devices have various rational arrangements according to different process requirements. 　　High-frequency welding is a type of welding method in which the resistance of the high-frequency current flowing through the continuous contact surface of the workpiece is heated by the electric resistance and the forging force is applied to realize the mutual connection between the workpiece metals. It is similar to ordinary resistance welding, but there are many important differences. 　　High-frequency welding has been used in carbon steel welded pipe production for more than 40 years. High-frequency welding has a large power supply, and can achieve a higher welding speed for steel pipes of different materials, calibers and wall thicknesses (...

　　According to different production methods, seamless steel tube can be divided into hot rolled tube, cold rolled tube, cold drawn tube and extruded tube. 　　1. Hot-rolled seamless pipes are generally produced on automatic rolling mills. The solid tube blank is inspected and the surface defects are removed, cut into the required length, centered on the end face of the perforated end of the tube blank, then sent to a heating furnace for heating and perforated on the punching machine. At the same time, the perforation is continuously rotated and advanced. Under the action of the roll and the head, a cavity is gradually formed inside the tube blank, which is called a capillary tube. It is sent to the automatic pipe mill for further rolling. Finally, the whole machine is uniform in wall thickness, and the sizing machine is sizing to meet the specification. The production of hot-rolled seamless steel tubes by continuous rolling mills is a more advanced method. 　　2. If you want to obtain ...

　　Methods for quality discrimination of large-caliber seamless steel: 　　1. The ingredients are uniformly large diameter seamless steel tonnage cold shear is also high, so smooth and neat end face of the cutting head, when you see the end face of the cutting head off the meat often have the appearance of, or rugged look dull large-diameter seamless steel pipe division, do not pick up these are defective in. 　　2. Under no circumstances vernier caliper, you need to be weighed checked shoddy large diameter seamless steel pipe due to impurities content and the density of steel is small, but the scale of tolerance is grim, so lightweight large-diameter seamless steel, do not pick and choose. 　　3. Look inside diameter of scale: large-diameter seamless steel pipe defective inner diameter larger scale will be shaken. 　　4. seen factory trademark: Excellent large diameter seamless steel pipe trademarks and printing are very standardized. 　　5. Look longitudinal reinforcement: large-diam...

　　 Seamless steel pipe in actual life is everywhere visible, only it in a different way appear in front of everyone's eyes, so that we also do not understand, such as car exhaust pipe and staircases, handrails, in into the machinery in use, can significantly the extension machinery use life and put into use in the days, the days for everyone to bring must guarantee. 　　Follow skills development, the quality of seamless steel pipe more assurance, allows users to use more centering. Face is not the same type of seamless steel tube, want to purchase a suitable you use seamless steel tube also exists certain degree of difficulty, the following with the pace from small series of come to find out, how should choose and buy seamless steel pipe. 　　Seamless steel pipe used standard is GB/T2102-2006, in the purchase of this seamless steel tube, needs friends pay attention to the packaging and quality guarantee. Cold rolling seamless steel pipe scale more accurate, this kind of seamless s...

　　Hot rolled seamless steel pipe , what advantages and disadvantages? Seamless steel tube after hot rolling, grain refinement of steel, destruction of ingot casting structure, and eliminates the defects of microstructures, the steel pipe dense tissue, mechanical properties improved. Before steel pipe in the presence of bubbles, cracks and loose, after hot rolling will be welding under high temperature and high pressure. 　　Although hot rolling seamless steel pipe has many advantages, but its shortcomings must be clear, steel pipe after hot rolling, nonmetallic inclusions in steel is pressed into sheets, and the stratification occurs. Layered make the steel along the thickness direction of the tensile performance deteriorated significantly, in the weld contraction appear torn between the layers. 　　Steel after hot rolling, must have advanced technology, if the technology, however clearance, steel pipe in hot rolling of uneven cooling caused by the residual stress. The residual stress ...

　　What are the advantages and disadvantages of hot-rolled seamless steel pipe ? Seamless steel hot-rolled, grain refinement of steel, steel ingot casting destroy tissue and eliminate defects in the microstructure, the resulting steel organization compacting, mechanical properties improved. before the existence of the bubble pipe, cracks and loose, after hot rolling at high temperature and pressure will be welded together. 　　Although hot-rolled seamless steel pipe has many advantages, but its shortcomings must be clear, after the hot-rolled steel, steel and non-metallic inclusions inside is pressed into thin slices, stratification. Stratification between the steel in the thickness direction of tension performance deteriorated significantly, there interlayer tear weld shrinkage. 　　Hot-rolled steel into too, must have advanced technology, if technology does not pass, steel uneven residual stress caused by cooling during hot rolling. Residual stress in the absence of external forces ar...

　　The electric resistance welding pipe machine is 3 to 5 times more efficient than conventional TIG welding. Afterwards, the TIG welding bottom sealing MIG welding filling and covering process was changed due to defects such as root incomplete penetration and cratering. The improved welding process basically solved the problem of insufficient penetration of the root, but reduced the welding efficiency. Increased investment in equipment and complicates operating procedures. 　　Recently, the hot pot TIG automatic pipe welding machine was introduced from abroad. The principle of hot wire TIG welding is to supply the filler wire from a separate constant voltage AC source before it is fed into the weld pool. The resistance is heated to a high temperature of 650-800 °C, which greatly accelerates the melting speed of the wire, and its deposition rate is close to the MTG welding deposition rate of the same diameter. 　　In addition, the good back sealing characteristics of the TIG method ensu...