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Black Steel Pipe Manufacturers

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  we are pre-galvanized steel pipe supplies,rectangle steel pipe wholesale,china round steel pipe exporter,you can know it.

       Executive Standard: ASTM.DIN,JIS,GB

  Grade: Q195-Q235

  Technology Data:

Black Oval Steel Pipe0.3740X0.6693-1.1811X2.36229.5X17-30-600.0118-0.07870.3-2.0

Steel pipe factory supplies a large number of specifications

There are more than 5,100 production steel pipe plants under the 1,450 companies in more than 110 countries producing steel pipes, including more than 260 plants under 170 companies in 44 countries.

Characteristics of steel pipes:

The thicker the wall thickness of the steel pipe, the more economical and practical it is. The thinner the wall thickness, the higher the processing cost of the steel pipe plant. Secondly, the process of the steel pipe plant determines the limited performance of the steel pipe, and the general seamless steel pipe Low precision: uneven wall thickness, low brightness inside and outside the tube, high fixed-length cost, and pitting and black spots on the inside and outside of the table are not easy to remove; third, its detection and shaping must be processed offline. Therefore, it embodies its superiority in high-pressure, high-strength, mechanical structural materials.

Type of steel pipe factory:

The rolling method is divided into hot rolling, hot extrusion and cold drawing (rolling) stainless steel tubes.

According to the stainless steel metallographic structure, it is divided into semi-ferritic semi-Martensitic stainless steel pipes, martensitic stainless steel pipes, austenitic stainless steel pipes, austenitic-ferritic iron stainless steel pipes.

Stainless steel tube specifications and appearance quality:

A. According to GB14975-94 "stainless steel seamless steel pipe", the normal length of steel pipe (indefinite) hot-rolled steel pipe is 1.5~10m, and the hot-extruded steel pipe is equal to or greater than 1m. Cold drawn (rolled) steel pipe wall thickness of 0.5 ~ 1.0mm, 1.0 ~ 7m; wall thickness greater than 1.0mm, 1.5 ~ 8m.

B. There are 45 kinds of hot-rolled (hot-extruded) steel pipes with a diameter of 54-480 mm; a total of 36 kinds of wall thicknesses of 4.5-45 mm. There are 65 kinds of cold drawn (rolled) steel pipes with a diameter of 6 to 200 mm, and 39 kinds of wall thicknesses of 0.5 to 21 mm.

C. There shall be no cracks, folds, cracks, cracks, rolling, separation and crusting defects on the inner and outer surfaces of the steel pipe. These defects shall be completely removed (except for mechanical processing pipes), and the wall thickness and outer wall shall not be removed after removal. The diameter exceeds the negative deviation. Other minor surface defects that do not exceed the allowable negative deviation may not be removed.

D. Straight road allows depth. Hot-rolled, hot-extruded steel pipe, diameter less than or equal to 140mm is not more than 5% of the nominal wall thickness, the maximum depth is not more than 0.5mm; cold drawn (rolled) steel pipe is not more than 4% of the nominal wall thickness, the maximum depth is not more than 0.3 Mm.

E. Both ends of the steel pipe should be cut at right angles and the burrs should be removed. Stainless steel pipe manufacturing process:

The raw material of the rolled steel pipe of the steel pipe plant is a round tube blank, and the round tube embryo is cut into a blank having a length of about 1 m by a cutting machine, and sent to a furnace for heating through a conveyor belt.

The billet is fed into a furnace and heated to a temperature of approximately 1200 degrees Celsius. The fuel is hydrogen or acetylene. Furnace temperature control is a key issue. After the round billet is released, it is subjected to a through-hole punching machine.

After the perforation of the steel pipe plant, the round billet is successively rolled, rolled or extruded by three rolls. After extrusion, the tube should be sizing. The sizing machine is rotated at a high speed by a conical drill bit into a steel core to form a steel pipe.

The inner diameter of the steel pipe is determined by the outer diameter of the sizing machine drill bit. After the steel pipe is sized by the steel pipe plant, it enters the cooling tower and is cooled by water spray. After the steel pipe is cooled, it is straightened.

The rolling method of cold drawn (rolled) seamless steel pipe is more complicated than hot rolling (extrusion seamless steel pipe). The first three steps of the production process of the steel pipe plant are basically the same. The difference begins with the fourth step. After the round billet is hollowed out, it is required to start and anneal.

After annealing, it is acid washed with a special acidic liquid. After pickling, apply oil. This is followed by a multi-pass cold drawing (cold rolling) of the blank tube, followed by a special heat treatment. After heat treatment, it is straightened.

After the steel pipe is straightened by the steel pipe plant, it is sent to the metal flaw detector (or water pressure test) by conveyor belt for internal flaw detection.

If there are cracks inside the steel pipe, bubbles and other problems will be detected. After the steel pipe quality inspection, it must be carefully selected by the steel pipe factory. After the steel pipe quality inspection, the steel pipe factory uses the paint to spray the number, specifications, production batch number and so on. It is hoisted into the warehouse by a crane.

20G steel pipe manufacturers production specifications

20G steel pipe is GB/5310 national standard steel number (foreign corresponding grade: Germany st45.8, Japan STB42, US SA106B), which is the most commonly used steel for boiler steel pipe. Its chemical composition and mechanical properties are basically the same as those of 20 plates. The steel has certain normal temperature and medium-high temperature strength, low carbon content, good plasticity and toughness, and good cold-hot forming and welding performance.

20G steel pipe is mainly used for manufacturing high-pressure and higher-parameter boiler pipe fittings, low-temperature section superheater, reheater, economizer and water wall; for example, small-diameter pipe is used for wall surface temperature ≤500°C heating surface pipe, and water wall pipe, Economizer tubes, etc., large-diameter tubes are used for steam pipes, headers (economizers, water-cooled walls, low-temperature superheaters and reheater headers) with wall temperature ≤ 450 °C, and medium temperature ≤ 450 °C pipeline accessories.

Since carbon steel will be graphitized after long-term operation above 450 °C, the long-term maximum use temperature of the tube as the heating surface is preferably limited to 450 °C or less. In this temperature range, the steel can meet the requirements of superheater and steam pipeline, and has good oxidation resistance, plastic toughness, welding performance and other cold and hot processing performance are very good, and the application is wide.

The steel used on the Iranian furnace (single unit) is the lower water inlet pipe (28 tons), the steam water inlet pipe (20 tons), the steam connection pipe (26 tons), and the economizer header (8 tons). The desuperheating water system (5 tons) is used as the flat steel and boom material (about 86 tons).

The 20g steel pipe manufacturer is a long strip of steel with a hollow section and no joints around it. Steel pipes have a hollow section and are used in large quantities as pipes for transporting fluids, such as pipes for transporting oil, natural gas, gas, water and certain solid materials.

Compared with solid steel such as round steel, the steel pipe is lighter in weight when it has the same bending and torsional strength. It is an economical section steel and is widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile transmission shafts, bicycles. Shelf and steel scaffolding used in construction.

The use of steel pipes to manufacture ring-shaped parts can improve the material utilization rate, simplify the manufacturing process, save materials and processing man-hours, such as rolling bearing rings, jack sleeves, etc., and have been widely used in steel pipes. Steel pipes are also indispensable materials for various conventional weapons, and barrels, barrels, etc. are all made of steel pipes.

Steel pipes can be divided into round pipes and shaped pipes according to the shape of the cross-sectional area. Since the area of the circle is the largest under the condition of equal circumference, more fluid can be transported by the circular tube. In addition, the circular section is subjected to a relatively uniform force when subjected to internal or external radial pressure, and therefore, most of the steel pipes are round pipes.

However, the round pipe also has certain limitations. For example, under the condition of being bent by the plane, the round pipe is not as strong as the square and rectangular pipe, and some agricultural machinery skeletons, steel wood furniture, etc. are commonly used for square and rectangular pipes. 20g steel pipe manufacturers also need other shaped steel pipes of different cross-sections according to different purposes.

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