The thickness of thick wall coiled pipe is generally greater than 20mm, and the outer diameter range is 450-3000mm. The thick wall coiled pipe is rolled under the condition of steel plate heating Welding, forming, rib, defect detection, factory. Sometimes the wall thickness is relatively thick and secondary heating is required. The feature is that the outer diameter tolerance is small Uniform wall thickness.
Welding voltage because the welding arc is conical, and the welding voltage directly affects the length of the arc. Therefore, with the increase of welding voltage, the arc length increases, the moving range of arc spots expands, the weld pool widens and a wider weld formation will be obtained. If welding is carried out in a horizontal position, it will only change the width of the weld without affecting the edge transition of the weld. However, the external welding of spiral welded pipe is carried out on the slope, and the molten weld metal will flow laterally under the action of gravity. It can be seen that the larger the welding voltage and the wider the weld pool, the more serious the trend of lateral flow of weld metal, * eventually leading to the bias flow of weld metal. Coil products are not only rich in types but also diversified in processing technology and molding. In most cases, after forming, the next process is to expand the diameter of the welded pipe blank to improve the quality of welded pipe shape. In other words, the expanding process has become an important process to ensure the quality of finished pipe in the production of large-diameter straight seam coiled pipe.
.Purpose of steel plate rolling: steel plate rolling is mostly used in large-scale steel structure construction as the main support part, such as bridge piling, seabed piling and high-rise building piling. Its material: Q345C. Q345D and Q345E are also used in low temperature areas.
During the plate crimping process, the steel plate can be sandblasted to eliminate the iron oxide scale on the surface of the steel plate and ensure the raw materials on the cylinder surface during the processing process.
.Welding voltage because the welding arc is conical, and the welding voltage directly affects the length of the arc. Therefore, the general production process of thick wall continuous pipe can be divided into cold drawing and hot rolling. The production process of cold rolled seamless steel pipe is generally more complex than that of hot rolled steel pipe. First, the pipe must be subject to winding diameter test. If there is no response crack on the surface, the round pipe will be cut and the growth of the blank is about M. However, during annealing, acid should be used for annealing, and attention should be paid to whether there are a large number of bubbles on the surface. If a large number of bubbles appear, the quality of the steel pipe will not meet the response standard. The appearance of cold-rolled seamless steel pipe is shorter than that of hot-rolled seamless steel pipe, and the wall thickness is generally smaller than that of hot-rolled seamless steel pipe, but the surface is brighter than that of thick wall seamless steel pipe, the surface is not too rough, the diameter is not too prickly and the strength is high. The manufacturer offers, operates in good faith, and has a real price. The same specification, spot supply, and complete specifications,. With the increase of welding voltage, the arc length increases, the moving range of solder joint increases and the molten pool widens. If welding is carried out in a horizontal position the weld width will be changed, but the edge transition of the weld will not be affected. However, the external welding of spiral welded pipe is carried out on the slope, and the molten weld metal will flow laterally under the action of gravity. We specialize in providing hot-rolled steel pipe, large-diameter thick wall continuous pipe, thick wall straight seam continuous pipe, steel casing and quality assurance of pipe rolling plant. During the preferential activities, new and old customers are welcome to consult. Therefore, the greater the welding voltage, the wider the weld pool, the more serious the transverse flow of weld metal, and finally lead to the bias of weld metal.
If the particle size of straight seam coiled pipe is too small, the adhesion and impact strength of the coating will be reduced. For serious internal pitting corrosion, it can not only rely on the high-strength impact of large particles of rinse agent, but also remove corrosion products with small particles. Reasonable ratio design can not only slow down the speed of pipeline and nozzle (propeller) rinse agent. Wear and tear, and the rate of rinsing agent can be greatly improved. Generally, the particle size of metal particles is 2 - 9mm, and the particle size of metal sand is 1 - 2mm, of which 3 - 5mm is a common component. The sand shot ratio is usually 4 to 9.
High manganese content 6 will make the steel brittle and reduce its plasticity. Under what circumstances does the thick wall coil need to be preheated before welding?
Move the steel pipe twice to weld and reinforce the rolled pipe joint, and then transport it to the welding platform for welding.
During handling, the damaged parts shall be protected. Raw materials include steel strip coil, thick wall large diameter steel plate coil, welding wire and flux. Strict physical and chemical inspection shall be carried out before input.
Pipe groove processing and joint pair: when the pipe wall thickness is less than 6mm, it is type I weld; when the pipe wall thickness is greater than 6mm, it is type V weld; For pipes with diameter greater than 600mm and wall thickness greater than 6mm, the bottom of the pipe shall be sealed at the bottom of the pipe; In addition to the lap joint, the other type of gas coil pipe is continuous and solid V-groove butt welding. If the weld is found to be defective, the weld must be re welded. Rewelding shall not be more than twice. The longitudinal weld of coiled pipe in the same cylindrical part shall not be greater than, and the spacing between two longitudinal joints shall not be less than 200mm.
Sincere service.Today's equipment is double-sided submerged arc welding because it goes without saying that double-sided welding is necessary here.
In general, the hot coil pipe is mainly committed to the production of all kinds of circumferential seam and longitudinal ring coils and steel penstocks. It is reformed on the basis of traditional coil equipment and similar specifications and models, so that all parameters of the hot coil pipe can be improved, filling the gap that the original traditional coil equipment can not produce. In addition, in terms of processing technology, the hot coil pipe needs attention. The following matters are required: before processing, the hot coil pipe needs to be familiar with the technical requirements of paper, process material properties and other related aspects, select an appropriate hot coil machine, determine whether the cold coil, warm coil or hot coil, and then operate.
The inner diameter of 1800mm steel plate coiled pipe elbow is 1800mm, the bending radius is also 1800mm, four bends, the material thickness is 4mm, and the bending is 90 & deg;.
Continuous pipe is committed to producing all kinds of circumferential seam, and is reformed on the basis of the same specification and model of traditional pipe rolling equipment.
Where can I find it?.In the production process the hot-rolled steel pipe has the characteristics of no raw materials, that is, the mechanical properties of thick wall steel plate. In this way, the steel plate is heated first and then rolled, which softens the steel plate under great conditions, which will not affect the material quality, nor damage the properties such as strength, yield and tensile strength. For the wall thickness that can not be achieved by cold rolled steel pipe, the specification and model of thick wall steel pipe are added.
The automation and mechanization level of large-diameter steel coil is not high, which requires a lot of manual treatment. The main problem of large-diameter coiled pipe is welding. As long as the flaw detection can be carried out, the wall thickness of coiled pipe is 20mm and the outer diameter is 450-
.Weld inspection is necessary to detect the weld quality of steel coil pipe. After welding, all the welds are tested by on-line continuous ultrasonic automatic flaw detector to ensure the NDT coverage of the welds. If there are defects, and the production will adjust the process parameters at any time to eliminate the defects in time.
The arc length of the coil calibration template shall be 1 / 6 ~ I of the circumference of the pipe / the gap between the template and the pipe. What is the manganese content of the straight seam coil? Q345B coil, manganese is a common element in structural steel. Manganese in carbon steel is mainly added to the steel water as deoxidizer in the steelmaking process, usually in the range of 0.3-0.8%. In low alloy steel, manganese is a mixed alloy element, welded pipe definition: the pipe formed by crimping the plate and strip into a pipe barrel with specified shape and size, and welding the joint with appropriate welding. Applied discipline: Material Science and Technology (level discipline); Fundamentals of materials science and Technology (level discipline); Material synthesis