45# welded steel pipeAnalysis of the working principle

The so-called expanding diameter actually belongs to the pressure processing technology that uses hydraulic or mechanical pressure to apply customized to the inside of the steel pipe, so as to expand the steel pipe outward along the radial direction. Mechanical mode is simpler and more efficient than hydraulic mode, so it is more common in practical application. In particular, it is adopted in the very advanced expanding process of several large-diameter straight seam rolling pipelines.

The inspection requirements for thick wall coiled pipe treatment are that the thick wall coiled pipe is made of steel plate. The thick wall coiled pipe can be divided into coiled pipe and hot rolled thick wall coiled pipe. Generally, the production process of thick wall coiled pipe can be divided into cold drawing and hot rolling. The production process of cold-rolled seamless steel pipe is generally more complex than hot rolling. Roll sizing test shall be carried out for the pipe blank first. If the surface does not respond to the crack, the round pipe shall be cut by a cutter and cut into a blank with a length of about meters. However, when entering the annealing process, acid shall be used for annealing, and attention shall be paid to whether a large number of bubbles are generated on the surface. If a large number of bubbles are generated, it indicates that the quality of steel pipe can not meet the response standard. In appearance, the cold-rolled seamless steel pipe is shorter than the hot-rolled seamless steel pipe, and its wall thickness is generally smaller than that of the hot-rolled seamless steel pipe, but the surface is brighter than that of the thick wall seamless steel pipe. There is not too much roughness on the surface and there are not too many burrs in the diameter. The thick wall coiled pipe is a powerful manufacturer, quotation, honest operation, genuine and of the same quality. The thick wall coiled pipe is available from stock, with complete specifications,. The wall thickness of coiled pipe is 20mm and the outer diameter is 450-3000mm. It is rolled, formed, butted, removed and reinforced directly from the steel plate. Coil processing time is short and delivery is fast.

.Both internal welding and external welding adopt American Lincoln Electric welding machine for single wire or double wire submerged arc welding, and large-diameter thick wall coil pipe,Q550b welded steel pipe,Q550b reel, so as to obtain stable welding specification.

Before starting up, it is necessary to check whether the hot coil machine operates normally and fill the oil hole with oil.

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

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.

Clean the iron oxide scale falling off in the process of plate drum to prevent the iron oxide scale from bonding and the surface of steel plate.

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

Thick wall coiled pipe is not only used to transport fluid and powdery solids, exchange heat energy, mechanical parts and containers, but also a kind of economic steel. Building structural grid with steel can reduce weight, save metal by 20 ~ 40%, and realize industrialized mechanized construction. Building highway bridges with steel can not only save steel and simplify construction, but also greatly reduce plot, investment and maintenance Maintenance cost. Thick wall coiled pipe is mainly used in tap water engineering, petrochemical industry, chemical industry, electric power industry, agricultural irrigation and urban construction. It is mainly used in tap water engineering, petrochemical industry, chemical industry, agricultural irrigation and urban construction. It is one of the key products of development. It is used for gas transmission: gas, steam and liquefied petroleum Gas: used as pile driving pipe, bridge, wharf, road, building structure pipe, etc.

The butt joint of coiled pipe (with the same wall thickness) shall not exceed 10% of the wall thickness and not more than 2mm.

Excellent quality.The process of heating the whole thick wall coil or welding area before welding is called preheating. For the steel with high welding strength grade, it has hardening trend, material, especially good thermal conductivity, weldment and large thickness. When the ambient temperature around the welding area is too low, it is necessary to preheat the weldment before welding.

When the nominal diameter is greater than or equal to 600mm, back welding shall be carried out in the pipe.

The products are widely used in petroleum, chemical industry,16Mn large diameter thick wall welded pipe, natural gas transportation, pile driving and urban water supply, heating, gas supply and other projects. The wall thickness of the hot-rolled thick wall coil of retailers generally exceeds 20mm, and the outer diameter range is 450-3000mm. The hot-rolled thick wall coil is rolled, welded, formed, de reinforced flaw detected and delivered under the state of steel plate heating. Sometimes the wall with special thickness needs secondary heating. It is characterized by small outer diameter tolerance and uniform wall thickness. The main thing is that the hot-rolled thick wall quality management coil will not damage the performance of raw materials. The disadvantages of hot-rolled thick wall coil are long processing time and the diameter of thick wall coil is generally above dn450.

steel products.

Quality department.Weld size has a great influence on the quality of rolled steel pipe. Weld size mainly includes welding process parameters, welding wire shape and position parameters, after repair, they shall be subject to nondestructive inspection again until it is confirmed that the butt weld of strip steel and the pipe of T-joint intersecting with spiral weld have all passed the X-ray television or film. Each steel plate coil has passed the hydrostatic test, and the pressure adopts radial sealing. The test pressure and time are strictly controlled by the microcomputer detection device of steel plate rolling pipe water pressure. Why are there two longitudinal welds in the same pipe section of rolling pipe?

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, 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.

.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, and the manganese content in 16Mn steel and 15MnV steel is 2-6%.

Generally, the packaging process of thick wall coiled pipe mainly includes filling, wrapping, 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.

Generally, the wall thickness of the rolled pipe is 20mm and the outer diameter is 450-3000mm. It is rolled, welded, formed, butted and rolled directly from the steel plate. It has the advantages of short processing time, fast delivery and low cost. The rolled pipe is mainly used for hot-rolled thick wall coils such as pipes, billboard and columns. The thickness of the hot-rolled thick wall coil is generally greater than 20mm and the outer diameter is 450-3000mm. The hot-rolled thick wall coil is rolled under the heating of the steel plate Welding, forming, deburring, defect detection and delivery. 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. It is important that the hot rolled thick wall coil will not damage the properties of raw materials. The disadvantages of hot roll thick wall rolling pipe are long processing time and. Hot rolled thick wall coils are widely used: cylinder hydraulic, bridge, roller table, etc.