Q355b large diameter thick wall welded pipeIntroduction to the correct purchase method

announcer:hp709HP180518493 release time:2022-01-08 23:34:52

Hot rolled steel pipe is a kind of thick wall steel pipe rolled under the condition of heating the steel plate.

Today's equipment is double-sided submerged arc welding, it is necessary to confirm whether the inner side is upward before plate rolling to ensure the correctness of groove direction.

.Chinese Name: welded pipe English Name: welded tube, 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 preparation and processing (level discipline); Plastic processing technology (level discipline) what are the main raw materials of electric welded steel pipe?

Hot rolled steel pipe is a kind of thick wall steel pipe rolled under the condition of heating the steel plate.

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, 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,45# thick wall coiled pipe, and the strength is high. The manufacturer offers, operates in good faith, and has a real price. The same specification, thick wall continuous pipe, 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.


Q355b large diameter thick wall welded pipeIntroduction to the correct purchase method



Generally, the packaging process of thick wall coiled pipe mainly includes filling, wrapping, sealing and other processes, as well as related pre and post processes, such as cleaning, stacking and disassembly. Because it is used strictly the process of thick wall rolling pipe shall be strict, and the production shall be carried out according to the correct methods and principles. In addition, the process of thick wall rolling pipe also includes stamping on the package. The use of mechanical packaging products can improve productivity, reduce labor intensity and meet the needs of large-scale production. Thick wall coiled pipe is developed with the emergence of new packaging materials and the continuous innovation of packaging technology. It can show important value in different industries and fields.

The welding method of welded steel pipe is submerged arc welding; Molding process forward swing intermittent production; Unit speed, 0.5 -- 3m / min; Welding speed, 0.5 -- 3m / min. The unit is composed of uncoiler, straightener, centering device, hydraulic shear, milling welding machine, disc shear, edge milling machine, plate surface cleaning equipment,45# large diameter thick wall welded pipe, delivery machine, plate edge pre bending equipment, forming machine, internal welding, external welding, flash, pulling out, slag pouring, repair welding, flat head chamfering, hydraulic inspection, finished product inspection and degreasing collection. The whole process of submerged arc welding of spiral steel pipe is as follows: the principle of spiral steel pipe submerged arc welding: submerged arc welding is welded with arc heat energy. The difference from manual electrode arc welding is that the welding wire of submerged arc welding is, and there is no coating on it. The flux of submerged arc welding is pre laid at the place to be welded. In the flux of submerged arc welding wire, the arc is under the flux. For welding wire and workpiece, when the start button is pressed, the welding wire and workpiece are energized, the welding wire is pulled back, the arc is ignited, the welding trolley moves forward, and the welding wire is continuously transported downward to maintain the arc under the flux layer and form a welding pool under the arc. Around the arc, the flux melts to form a cavity. The cavity and molten pool advance continuously, and the metal behind the molten pool solidifies to form a continuous weld. This process is carried out under flux, so we can't see it. It can be seen by means of X-ray photography. Because the spiral steel pipe adopts the welding technology of submerged arc automatic welding, in addition to this, the production efficiency is high; The auxiliary time of production is less, which saves the time of electrode replacement; The welding conditions are clean, saving the cleaning time; High weld quality. It also provides necessary conditions for the delivery of spiral steel pipe factory, so it is still widely used.

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.

Scheme customization.Because the coiled steel pipe plays an important role in construction, railway construction and bridge construction, its quality standards are also more important. If you don't understand the quality specifications and standards, column, conveying fluid, pressure vessel, etc. The longitudinal weld of the same barrel section of high pressure and high temperature continuous pipe shall not exceed two courses, and the spacing between the two longitudinal welds shall not be less than 200mm.


Q355b large diameter thick wall welded pipeIntroduction to the correct purchase method



The effect of antirust oil on thick wall coiled pipe is antirust effect, it has moisture-proof performance, uses antirust oil to isolate the direct air of thick wall welded pipe, so it has little chance of being changed by the external situation, which increases its stable performance and safer use.

Quality inspection report.Meet the following requirements: 1. The longitudinal joint of butt joint shall not be greater than 10% of the wall thickness plus 2mm, and shall not be greater than 3mm. 2. The longitudinal joint of joint 200mm away from the pipe end shall not be greater than 2mm. 3. Other parts shall not be greater than 1mm. 4. The vertical deviation between the end face of coiled pipe and the center line shall not be greater than percent of the outer diameter of pipe and shall not be greater than 3mm. The straightness deviation shall not exceed 1mm / m. 5 the weld cannot be double-sided molded coiled pipe. When the nominal diameter is greater than or equal to 600mm it is recommended to seal and seal in the pipe. In order to obtain better uniform cleanliness and roughness distribution, the particle size and proportion design of rinse agent is very important. The roughness is too large, which may cause the anti-corrosion layer to become thinner at the peak of the cloud path. At the same time, because the cloud path is too deep, bubbles are easy to form in the process, which seriously affects the performance of the layer.

Generally, the wall thickness of the coil is 20mm and the outer diameter is 450-3000mm. It is directly rolled and welded from the steel plate. It has the advantages of short processing time, fast delivery and low cost. Coil is mainly used for pipes, billboards, etc.

The main purpose of preheating is to reduce the cooling rate of welded joints and preheat temperature. As can be seen from the table, preheating can reduce the cooling rate, but basically does not affect the time spent at high temperature, which is ideal. Therefore, when welding thick wall coils with hardening trend, the main technical measure to reduce the cooling rate and hardening trend is preheating rather than increasing the line energy. Plasma cutting of thick wall coiled pipe is more effective than gas cutting

.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.

Rolled pipe is divided into straight seam rolled pipe and T-shaped welded pipe. The pipe rolling can meet the market demand for less number and more models of welded pipes. It can be used for pipe pile, column, conveying fluid, pressure vessel, etc. The longitudinal weld of the same barrel section of high pressure and high temperature continuous pipe shall not exceed two courses, and the spacing between the two longitudinal welds shall not be less than 200mm.

Move the steel pipe twice to weld and reinforce the rolled pipe joint, and then transport it to the welding platform for welding.