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
Continuous pipe products are widely used in petroleum, chemical industry, natural gas transmission, pile driving, urban water supply, gas supply and other projects. The detection of thick wall continuous pipe is mainly ultrasonic flaw detection. The longitudinal wall thickness of two cylinders should not exceed two. The butt weld of thick wall continuous pipe shall be flush with the. When the nominal diameter is larger than, back sealing welding shall be carried out in the pipe. In the process of pipe rolling, the rolling quality of pipe, Q235B rolling, Q345B rolling, large diameter thin wall rolling, large diameter thick wall rolling, stainless steel rolling, L360 rolling and 16Mn rolling were analyzed. The offer is in progress. Welcome new and old customers to consult. Prevent surface damage of steel plate.
.In addition, pressure design or analytical analysis shall be carried out according to relevant regulations to determine its use basis. In addition, the strength grade of pipe fittings shall not be lower than the pressure under severe working conditions encountered by the whole pipeline.
Due to the continuous application of thick wall coiled pipe in industry and the continuous expansion of its scope, it has many advantages. In order to prevent the thick wall coiled pipe from rusting, we can apply antirust oil on the surface of the thick wall coiled pipe.
.Since the groove sizes of longitudinal and circumferential joints of hot-rolled pipes are different, it is necessary to confirm whether the inner side is upward before plate rolling to ensure the correctness of groove direction.
However the disadvantages of manual cutting and cutting are also obvious, and the quality of the incision is very poor Big size error There is a great waste of materials The post-treatment process has large processing capacity and poor working conditions. Cutting with a forming machine can greatly improve the quality of the workpiece, but the workpiece must be pre machined. It is not suitable for blanking of single chip, small batch and large workpiece. Although the semi-automatic cutting machine reduces the labor intensity, its function is simple and is only suitable for cutting two shapes. Due to the low cost of equipment, the above cutting is easy to operate compared with CNC cutting Easy to operate, it is still widely used in small and medium-sized enterprises.
When the nominal diameter is greater than or equal to 600mm, back welding shall be carried out in the pipe.
Application of hot rolled steel pipe: the disadvantage of changing hot rolled steel pipe into seamless steel pipe with fixed specification and model is another major feature of hot rolled steel pipe. In the production process, hot rolled steel pipe has been widely used, especially in large equipment such as oil cylinder production, bridge construction, engineering column, large drum and so on. Save materials and labor for the above enterprises, reduce production costs, improve the market competitiveness of finished products, and promote the development of enterprises to a certain extent. Continuous pipe is committed to producing all kinds of circumferential seam, longitudinal circumferential continuous pipe and penstock, and is reformed on the basis of the same specification and model of traditional pipe rolling equipment. The function of parameters of pipe rolling equipment is improved by 30%, which fills the gap that can not be produced by traditional steel rolling equipment. It can produce steel pipes with diameter of more than 400 and wall thickness of 8-100mm.
The principle of encoder length measurement is to install an encoder at the oil cylinder, the oil cylinder pushes the welded steel pipe to move on the roller table, and a series of photoelectric switches with equal distance are installed on the other side. When the steel pipe is pushed by the oil cylinder and the pipe end touches the photoelectric switch, the distance of the oil cylinder can be converted from the recorded encoder reading, so that the length of the steel pipe can be calculated.
For external welding, a larger welding current is used. However, the stirring effect of molten pool is enhanced, and the melting amount of welding wire increases accordingly, resulting in the increase of weld reinforcement, the deterioration of weld formation and poor edge transition.
Packaging strategy.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?
Continuous pipe products are widely used in petroleum, chemical industry, natural gas transmission, pile driving, urban water supply, heat supply, gas supply and other projects. The detection of thick wall continuous pipe is mainly ultrasonic flaw detection. The longitudinal weld of the same barrel section of thick wall continuous pipe shall not exceed two passes. The butt weld of thick wall continuous pipe shall be flush with the. When the nominal diameter is larger than back sealing welding shall be carried out in the pipe. In the process of pipe rolling, the rolling quality of pipe, Q235B rolling, Q345B rolling, large diameter thin wall rolling, large diameter thick wall rolling, stainless steel rolling, L360 rolling and 16Mn rolling were analyzed. Professional hot rolled steel pipe, large diameter thick wall rolling pipe, thick wall straight seam rolling pipe steel casing, rolling pipe factory, large quantity, fire resistance - Waterproof - high temperature resistance, strong and durable, safe and reliable
In fact, the surface pit of the coiled pipe is almost caused by the sparse iron oxide scale on the surface of the steel plate. In general, we can apply the following methods for prevention.
The distance between the longitudinal joints of two pipes shall be greater than 100 mm. The distance between the outer wall of the branch pipe and the weld shall not be less than 50mm.
market price.Steel plate materials mainly include Q235, Q345, 20, 45, 35cimo and 42cimo, with 16 manganese and 16 manganese capacity. Generally, chemicals, natural gas transportation, piling and urban water supply, heating, gas supply and other projects can be customized! The required thickness and length can be adjusted as required! The rolling pipe weld is a double-sided weld. Two longitudinal welds are allowed, and the weld spacing exceeds 300 mm. The welding appearance and quality standard shall not be lower than the level standard in the welding specification.
Raw materials such as ferric chloride are prepared into corrosive solution in proportion. Generally, the 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 rolling. The pipe blank must first be tested for coil diameter. If there is no response crack on the surface the round pipe shall be cut into a blank with a length of about m by a cutter, 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 attention shall be paid to whether there are a large number of bubbles on the surface. If a large number of bubbles appear, 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,16Mn large diameter welded 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, and complete specifications,. Then, the observed metallographic samples were put into it for deep corrosion. Professional hot rolled steel pipe, large diameter thick wall rolling pipe, thick wall straight seam rolling pipe, steel casing, rolling pipe factory, high price,Q355b welded steel pipe, on-site settlement,20# large diameter thick wall welded pipe, honest operation! The corroded sample is cleaned in the ultrasonic generator after cleaning, and the powder falling off the sample during ultrasonic cleaning is collected for filtration and drying to obtain the carbide particles falling off the sample after corrosion. The pipe rolling plant will conduct scanning electron microscope and energy spectrum analysis on the cleaned samples and collected carbonization. What is the application of pressure perforation in pipe rolling production?
, low cost. The rolling pipe is mainly used for pipes, billboards, columns, etc.
.1 carbon structural steel: q215-a, q215-a. & middot; F,Q215-B,Q215-B· F,Q235-A,Q235-A· F,Q235-B,Q235-B· F. Q235-c ordinary carbon steel: B2 BY2 B2F by2f B3 by3 B3F by3f a2ay2 a2f ay2f A3 ay3 A3F ay3f2 high quality carbon steel: 10 15 20 transmission shaft steel 3 low alloy structural steel: 123mn 16Mn 19mn 08ti 10ti15ti4 special purpose steel plates are stacked in the open air to prevent rain from causing steel plates. The oxide scale falling off the surface of steel plates is easy to turn into blocks or clusters and adhere to steel plates or crimping rollers, When repeatedly pressed, the coiled pipe forms pit defects.
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.
Compared with seamless steel pipe, thick wall rolling pipe has the disadvantages of low cost, rapid delivery breaking the fixed specification of seamless steel pipe, etc. Thick wall coiled pipe is made of steel plate or steel strip by bending and then welding. According to the weld form, it is divided into straight welded pipe and spiral welded pipe. According to the purpose, galvanized welded pipe, oxygen blowing welded pipe, wire sleeve, metric welded pipe, idler pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welding thin-wall pipe, electric welding special-shaped pipe and spiral welded pipe. Rolling pipe is committed to producing all kinds of rolling pipes and steel penstocks with circumferential seam and longitudinal ring, and is reformed on the basis of similar specifications and models of traditional rolling equipment. The function of improving the parameters of the rolling and welding steel pipe equipment by 30% fills the gap that the original traditional rolling equipment can not produce. It can produce steel pipes with diameter of more than 400 and wall thickness of 8-100mm. Materials mainly include q23 q34 20#, 16 manganese, 16 manganese capacity, etc. Product executive standard: GB / t50205-200, GB / t3092-2001, etc. The products are widely used in petroleum, chemical industry, natural gas transportation, pile driving and urban water supply, heating, gas supply and other projects.