45# large diameter welded pipeDemand weakens or remains under pressure in the short term

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.

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.

.Starting from the service life of tools and the surface quality of pipes, the requirements are more stringent. For example, the hot furnace is divided into heating furnace and reheating furnace according to their functions. The former uses heat to the processing temperature; the latter is used to reheat the blank to the necessary processing temperature in the processing process. There are many forms of heating furnace, but the ring heating furnace is mainly used. This furnace bottom, it can be heated and homogenized to the specified temperature. The furnace process is relatively slow, and the heating operation needs patience. Because if the heating operation is not standardized, cracks, with the increase of welding voltage, the arc length increases, the moving range of arc spots expands, the weld pool widens, 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, 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,Q460b large diameter welded pipe, 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.

.The pipeline installation sequence is based on the principle of sub area and sub system, with small diameter, from the lower layer to the upper layer,Q460b large diameter thick wall coiled pipe, from difficult to easy, from the pipe gallery to the equipment. In principle, the pipeline connected with the machine is configured from the inside to the outside to reduce the impact of welding stress on the installation accuracy of the machine. The interface between indoor and outdoor pipelines shall be left outdoors. Q345B thick wall coiled pipe is a kind of material in carbon steel and is widely used. The thickness of Q345B thick wall coiled pipe is generally more than 10mm, which is widely used in drainage engineering, sewage pipeline, dredging pipeline, construction pipeline, etc. Q345B thick wall coiled pipe is a welded pipe product, and the process in the welded pipe is relatively simple and flexible. This type of steel pipe usually has no inventory and is processed by user. If the quantity is small, the raw materials are not good. The main problem of Q345B thick wall coiled pipe is welding. As long as it is possible, the delivery related requirements can be compared with other products.

Electric fusion connection: when the pipe fittings leave the factory, the resistance wire is buried in the pipe fittings to make electric fusion pipe fittings. At the construction site, only the plug of the special welding instrument and the socket of the pipe fittings need to be connected. The inner body of the pipe fittings melts the outer plastic of the pipe fittings and the inner plastic of the pipe fittings to form a reliable connection, and combines the timing methods such as special digital timekeeper and installation indicator hole.

Thick wall coiled pipe is made of steel plate. Thick wall coiled pipe can be divided into coiled pipe and thick wall coiled pipe. The wall thickness of coiled pipe is 20mm and the outer diameter is 450-3000mm. It is rolled, welded formed, butted, removed and reinforced directly from the steel plate. Coil pipe processing time is short and delivery is fast Low cost. The rolling pipe is mainly used for pipes, billboards, columns, etc.

The effect of antirust oil on thick wall coiled pipe is antirust effect, which can make the thick wall coiled pipe as smooth as new for a long time and reduce the external corrosion to it. It can also increase its sealing performance and ensure that there will be no problems when transporting fluid. In addition it has moisture-proof performance,Q460b thick wall coiled pipe, 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.

Hot coil thick wall pipe rolling process before hot coil thick wall pipe processing, you must be familiar with the technical requirements such as paper and process material properties, select an appropriate hot coil machine, and determine whether cold coil, warm coil or hot coil.

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.

Manufacturing cost.The thickness of hot-rolled thick wall coil is generally greater than 20mm, and the outer diameter range is 450-3000mm. The hot-rolled thick wall coil is rolled, welded, formed, ribbed and defect detection under the condition of steel plate heating. Sometimes the wall thickness is relatively thick and secondary heating is required. It is characterized by small outer diameter tolerance and uniform wall thickness. It is important that the hot rolled thick wall coil will not damage the properties of raw materials. The disadvantage of hot roll thick wall rolling pipe is that the treatment time is long. Hot rolled thick wall coiled pipe is widely used: cylinder hydraulic, bridge, roller, etc.

During pipe rolling, the surface damage of steel plate shall be prevented. The parts with serious scratches must be polished for transition, and the wall thickness of the polished parts shall not be less than the design wall thickness.

Have we learned about the packaging process of the steel used? Today, let's discuss the packaging process of lower thick wall coil.

Main technical measures for low hardening trend

knowledge.What is the manganese content of straight seam coiled pipe? The material of straight seam coiled pipe and an appropriate amount of manganese 1 can significantly improve the cold brittleness of straight seam steel pipe steel, increase the yield strength and tensile strength, reduce the plasticity and impact toughness, and do not be too large; 4 manganese has an effect on the removal of harmful element oxygen in steel; 5MN can also be used to synthesize high melting point (about 1600 ℃, much higher than the general processing temperature of steel), which is at high temperature in steel, so it can reduce the harmful effect of sulfur and lead to hot processing of steel. Sulfur cracked & ldquo; Hot crisp & rdquo; The phenomenon has decreased.

Thick wall coil production process thick wall coil production process can be divided into cold drawing, cold rolling, hot rolling and hot expansion.

The main problem of thick wall coiled pipe is welding. As long as flaw detection can be carried out, the requirements related to delivery are wider than other products. The detection of thick wall coiled pipe is mainly ultrasonic flaw detector.

.Finish machining is performed below, and after shot peening, the scales on the inner and outer surfaces of the elbow are removed and both ends are processed with grooves to facilitate welding.

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, it is divided into general welded pipe, 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, pile driving and urban water supply heating, gas supply and other projects.

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;.