Thick-walled pipes are also called thick-walled steel pipes. Steel pipes whose outer diameter to wall thickness ratio is less than 20 are called thick-walled steel pipes. It is mainly used as petroleum geological drilling pipes, cracking pipes for petrochemical industry, boiler pipes, bearing pipes, and high-precision structural pipes for automobiles, tractors, and aviation.
Chinese name thick-walled tube Foreign name thick-walled tube [1] Origin Liaocheng Specification 16-824×2-100 Material 10#, 20#, 35#, 45#, 16Mn 27SiMn Purpose Manufacturing pipes, containers, equipment, pipe fittings and steel Structural standard GB/T8162-2018 also known as thick-walled steel pipe
Table of contents
1 Product introduction
▪ Commonly used steel pipes
▪ Implement standards
2 Manufacturing process
▪ Hot rolled
▪ Cold drawn
3 Heat treatment technology
▪ Promote applications
▪ Heat treatment equipment
▪ Nitriding furnace
▪ Gas radiant tubes
Product introduction editor broadcast
Commonly used steel pipes
GB/T8163-1999 (Seamless steel pipe for conveying fluids): Mainly used for conveying fluid pipelines in engineering and large-scale equipment. Representative materials (grades) are 20, Q345, etc.
GB3087-1999 (seamless steel pipe for low and medium pressure boilers): mainly used for pipelines transporting low and medium pressure fluids in industrial boilers and domestic boilers. Representative materials are 10 and 20 gauge steel.
GB5310-1995 (seamless steel pipe for high-pressure boilers): mainly used for high-temperature and high-pressure resistant transport flows in power station and nuclear power plant boilers. Collective boxes and pipes. Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.
GB5312-1999 (Carbon steel and carbon-manganese steel seamless steel pipes for ships): Mainly used for Class I and II pressure-resistant pipes for ship boilers and superheaters. Representative materials are 360, 410, 460 steel grades, etc.
GB1479-2000 (seamless steel pipe for high-pressure fertilizer equipment): mainly used for conveying high-temperature and high-pressure fluid pipelines on fertilizer equipment. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.
GB9948-1988 (seamless steel pipe for petroleum cracking): mainly used in boilers, heat exchangers and fluid transport pipelines in petroleum smelting plants. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.
GB18248-2000 (seamless steel pipe for gas cylinders): mainly used to make various gas and hydraulic gas cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.
GB/T17396-1998 (Hot-rolled seamless steel pipe for hydraulic props): Mainly used to make hydraulic supports, cylinders and columns in coal mines, as well as other hydraulic cylinders and columns. Its representative materials are 20, 45, 27SiMn, etc.
GB3093-1986 (High-pressure seamless steel pipe for diesel engines): Mainly used for high-pressure oil pipes in diesel engine injection systems. The steel pipe is generally cold drawn pipe, and its representative material is 20A.
GB/T3639-1983 (cold-drawn or cold-rolled precision seamless steel pipe): Mainly used for mechanical structures and carbon pressing equipment, requiring high dimensional accuracy and good surface finish. Its representative materials are 20, 45 steel, etc.
GB/T3094-1986 (cold-drawn seamless steel pipes and special-shaped steel pipes): Mainly used to make various structural parts and parts. The materials are high-quality carbon structural steel and low-alloy structural steel.
GB/T8713-1988 (Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders): Mainly used to make cold-drawn or cold-rolled seamless steel pipes with precision inner diameter for hydraulic and pneumatic cylinders. Its representative materials are 20, 45 steel, etc.
GB13296-1991 (stainless steel seamless steel pipes for boilers and heat exchangers): mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. in chemical companies. High temperature, high pressure and corrosion resistant steel pipes are used. Its representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.
GB/T14975-1994 (Stainless Steel Seamless Steel Pipe for Structural Use): Steel pipes that are resistant to atmospheric and acid corrosion and have a certain strength are mainly used for general structures (hotel, restaurant decoration) and mechanical structures of chemical companies. Its representative materials are 0-3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc. [2]
Implementation standards
1. Structural seamless steel pipe (GB/T8162-2008) is a seamless steel pipe used for general structures and mechanical structures.
2. Seamless steel pipes for fluid transportation (GB/T8163-2008) are general seamless steel pipes used to transport fluids such as water, oil, and gas.
3. Seamless steel pipes for low and medium pressure boilers (GB3087-2008) are used to manufacture superheated steam pipes, boiling water pipes for low and medium pressure boilers of various structures, and superheated steam pipes, large smoke pipes, small smoke pipes and arch bricks for locomotive boilers. High-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel pipes for pipes.
4. Seamless steel pipes for high-pressure boilers (GB5310-2008) are high-quality carbon steel, alloy steel and stainless heat-resistant steel seamless steel pipes used for the heating surfaces of water tube boilers with high pressures and above.
5. High-pressure seamless steel pipes for fertilizer equipment (GB6479-2000) are high-quality carbon structural steel and alloy steel seamless steel pipes suitable for chemical equipment and pipelines with working temperatures of -40~400ºC and working pressures of 10~30Ma.
6. Seamless steel pipes for petroleum cracking (GB9948-2006) are seamless steel pipes suitable for furnace tubes, heat exchangers and pipelines in petroleum refineries.
7. Steel pipes for geological drilling (YB235-70) are steel pipes used by geological departments for core drilling. They can be divided into drill pipes, drill collars, core pipes, casings and sedimentation pipes according to their uses.
8. Seamless steel pipe for diamond core drilling (GB3423-82) is a seamless steel pipe used for drill pipe, core rod and casing for diamond core drilling.
9. Oil drilling pipe (YB528-65) is a seamless steel pipe with internal or external thickening at both ends used for oil drilling. There are two types of steel pipes: wired and unthreaded. Threaded pipes are connected with joints, while non-threaded pipes are connected with tool joints by butt welding.
10. Carbon steel seamless steel pipes for ships (GB5213-85) are carbon steel seamless steel pipes used in manufacturing ships' Class I pressure-resistant piping systems, Class II pressure-resistant piping systems, boilers and superheaters. The working temperature of the carbon steel seamless steel pipe wall does not exceed 450°C, and the working temperature of the alloy steel seamless steel pipe wall exceeds 450°C.
11. Seamless steel pipe for automobile half-shaft casing (GB3088-82) is a high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipe used for manufacturing automobile half-shaft casings and drive axle housing shaft tubes.
12. High-pressure oil pipe for diesel engine (GB3093-86) is a cold-drawn seamless steel pipe used to manufacture high-pressure pipes for diesel engine injection systems.
13. Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders (GB8713-88) is a cold-drawn or cold-rolled precision seamless steel pipe with precise inner diameter for manufacturing hydraulic and pneumatic cylinders.
14. Cold-drawn or cold-rolled precision seamless steel pipe (GB3639-83) is a cold-drawn or cold-rolled precision seamless steel pipe with high dimensional accuracy and good surface finish used in mechanical structures and hydraulic equipment. The use of precision seamless steel pipes to manufacture mechanical structures or hydraulic equipment can greatly save machining hours, improve material utilization, and at the same time help improve product quality.
15. Stainless steel seamless steel pipe for structural use (GB/T14975-2002) is a hot-rolled ( extruded, expanded) and cold drawn (rolled) seamless steel pipes.
16. Stainless steel seamless steel pipes for fluid transportation (GB/T14976-2002) are hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless steel pipes made of stainless steel used to transport fluids.
17. Special-shaped seamless steel pipe is a general term for seamless steel pipes with other cross-sectional shapes except round pipes. According to the different cross-sectional shapes and sizes of steel pipes, they can be divided into special-shaped seamless steel pipes with equal wall thickness (code-named D), special-shaped seamless steel pipes with unequal wall thickness (code-named BD), and variable-diameter special-shaped seamless steel pipes (code-named BJ). Special-shaped seamless steel pipes are widely used in various structural parts, tools and mechanical parts. Compared with round pipes, special-shaped pipes generally have a larger moment of inertia and section modulus, and have greater bending and torsion resistance, which can greatly reduce the weight of the structure and save steel.
Manufacturing process editor broadcast
hot rolled
(Extruded seamless steel pipe): round tube blank → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → tube removal → sizing (or diameter reduction) → cooling → straightening → hydraulic test (or flaw detection) →mark→warehouse
The raw material for rolling seamless pipes is round tube billet. The round tube billet must be cut by a cutting machine into a billet with a length of about 1 meter and sent to the furnace for heating via a conveyor belt. The billet is fed into the furnace and heated to a temperature of approximately 1200°C. The fuel is hydrogen or acetylene. Temperature control in the furnace is a key issue. After the round tube comes out of the furnace, it must be pierced through a pressure punching machine. Generally, the more common piercing machine is the tapered roller piercing machine. This type of piercing machine has high production efficiency, good product quality, large perforation diameter expansion, and can penetrate a variety of steel types. After perforation, the round tube blank is successively cross-rolled, continuous rolled or extruded by three rollers. After extrusion, the pipe should be removed and calibrated. The sizing machine rotates a tapered drill bit at high speed into the steel blank to drill holes to form a steel pipe. The inner diameter of the steel pipe is determined by the outer diameter length of the drill bit of the sizing machine. After the steel pipe is sized, it enters the cooling tower and is cooled by spraying water. After the steel pipe is cooled, it will be straightened. After straightening, the steel pipe is sent to the metal flaw detector (or hydraulic test) by the conveyor belt for internal flaw detection. If there are cracks, bubbles and other problems inside the steel pipe, they will be detected. After quality inspection, steel pipes must undergo strict manual selection. After the quality inspection of the steel pipe, spray the serial number, specification, production batch number, etc. with paint. And it is hoisted into the warehouse by a crane.
Cold drawn
Seamless steel pipe: round tube blank → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening → hydraulic test (flaw detection) → Mark → Warehouse.
Heat treatment technology editor broadcast
Promote application
Foreign heat treatment manufacturers attach great importance to cooling during the heat treatment process. According to the technical and process requirements of 12Cr1MoV structural alloy steel pipe, slow cooling, oil quenching cooling, one-time gas quenching cooling, etc. can be performed. Rapid atmosphere circulation cooling uses high-pressure gas injection into the cooling chamber, and the computer controls the changes in flow rate and flow rate to achieve the cooling rate within a specific time, thereby achieving the required cooling curve during the heat treatment process and ensuring the heat treatment quality of the 12Cr1MoV structural alloy steel pipe. In the past, the quenching gases that were cooled by gas quenching included nitrogen, helium, etc., but now air is sprayed intensively to cool the 12Cr1MoV structural alloy steel pipe at an extremely fast speed. After quenching, the surface only has a very thin oxide film, which is gray-white, 12Cr1MoV The color of the structural alloy steel pipe is still beautiful, and a large amount of nitrogen and inert gas are saved, further reducing the heat treatment cost.
The combination of vacuum low-pressure carburizing and high-pressure gas quenching is an advanced carburizing and quenching process today. It has the characteristics of fast carburizing speed, excellent carbide structure, small quenching cracking and deformation, saving energy and carburizing agent raw materials, carburizing 12Cr1MoV Structural alloy steel pipes have the characteristics of good surface quality and environmental protection.
Heat treatment equipment
All devices that require cooling, such as fan cooling, heat exchanger cooling, quenching oil tank cooling, etc., all adopt oil-sealed self-cooling, completely replacing the water-cooling circulation system, and the entire heat treatment furnace does not require any cooling water. For example, hot air circulation fan cooling: replace the original water-cooling jacket inlet and outlet pipes with oil pipes, place a small oil tank with a diameter of 102mm close to the fan, and the oil cooling system is fully closed. When the fan bearings have heat increase, the proportion of heated oil is small. , naturally floats upward, causing the oil to circulate naturally. In the case of small fuel tank storage and natural heat dissipation, the hot oil is cooled and then added to the circulation, completely replacing water cooling without consuming fuel and requiring no power. The water in the quenching oil tank plate heat exchanger is replaced by cooling oil. The cooling oil is heated by the heat exchange of the hot oil. The change in the specific gravity of the oil causes the cooling oil to circulate itself. A heat sink is added to the oil tank on the top of the furnace to cooperate with the fan. function to achieve the effect of full oil cooling and save a large amount of cooling water.
Nitriding furnace
Germany's Ipsen Company has applied hydrogen probes and corresponding technologies to measure and control the nitrogen potential in nitriding furnaces to adjust and control the nitriding furnace atmosphere and realize the modernization of nitriding furnaces.
gas radiant tube
Heated using natural gas. Gas heating technology and equipment are very mature in Europe. There are standard series of natural gas burners, which are manufactured and supplied by professional burner factories. The inner tube of the gas radiant tube has been changed from stainless steel to ceramic to extend the service life and increase the power. Natural gas heating improves energy utilization and reduces production costs.
Zhengde Welded steel pipe, also known as welded pipe, is a steel pipe made by welding steel plates or strips after being rolled and formed. Welded steel pipes are divided into straight seam welded pipes and spiral welded pipes according to the form of welds. Classified by production method: arc welded pipe, resistance welded pipe, (high-frequency, low-frequency) gas welded pipe, furnace welded pipe. The production process of straight seam welded pipe is simple, with high production efficiency, low cost, and rapid development. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. Narrow billets can be used to produce larger diameter welded pipes, and billets of the same width can also be used to produce welded pipes of different diameters. However, compared to straight seam pipes of the same length, the weld length increases by 30-100% and the production speed is lower. Thick wall coil products include: large coil, large diameter thick wall coil, various materials thick wall coil, hot rolled thick wall coil, cold rolled thick wall coil, etc.
All welded pipes can be made into galvanized welded pipes, which can be found through product consultation on the homepage.
| DN |
Welded steel pipe (ordinary) |
Welded steel pipe (thickened) |
Seamless steel pipe (hot rolled) |
Spiral welded steel pipe |
| pg≤1.0Mpa |
pg≤1.6Mpa |
pg≤2.5Mpa |
pg≤1.6Mpa |
| |
D×∮ |
(Kg/m) |
D×∮ |
(Kg/m) |
D×∮ |
(Kg/m) |
D×∮ |
(Kg/m) |
| DN15 |
21.3*2.75 |
1.25 |
21.3*3.25 |
1.44 |
---- |
---- |
---- |
---- |
| DN20 |
26.8*2.75 |
1.63 |
26.8*3.5 |
2.01 |
---- |
---- |
---- |
---- |
| DN25 |
33.5*3.25 |
2.42 |
33.5*4 |
2.91 |
32*3.5 |
2.46 |
---- |
---- |
| DN32 |
42.3*3.25 |
3.13 |
42.3*4 |
3.77 |
38*3.5 |
2.98 |
---- |
---- |
| DN40 |
48*3.5 |
3.84 |
48*4.25 |
4.58 |
45*3.5 |
3.58 |
---- |
---- |
| DN50 |
60*3.5 |
4.88 |
60*4.5 |
6.16 |
57*3.5 |
4.62 |
---- |
---- |
| DN65 |
75.5*3.75 |
6.64 |
75.5*4.5 |
7.88 |
73*4 |
6.81 |
---- |
---- |
| DN80 |
88.5*4 |
8.34 |
88.5*4.75 |
9.81 |
89*4 |
8.38 |
---- |
---- |
| DN100 |
114*4 |
10.85 |
114*5 |
13.44 |
108*4 |
10.26 |
---- |
---- |
| DN125 |
140*4.5 |
15.04 |
140*4.5 |
18.24 |
133*4 |
12.72 |
---- |
---- |
| DN150 |
165*4.5 |
17.81 |
165*5.5 |
21.63 |
159*4.5 |
17.14 |
168*5 |
20.1 |
| DN200 |
---- |
---- |
---- |
---- |
219*6 |
31.52 |
219*5 |
31.52 |
| DN250 |
---- |
---- |
---- |
---- |
273*8 |
52.28 |
273*7 |
45.92 |
| DN300 |
---- |
---- |
---- |
---- |
325*8 |
62.54 |
325*7 |
54.9 |
| DN350 |
---- |
---- |
---- |
---- |
377*9 |
81.67 |
377*7 |
63.87 |
| DN400 |
---- |
---- |
---- |
---- |
426*9 |
92.55 |
426*7 |
72.33 |
| DN450 |
---- |
---- |
---- |
---- |
480*9 |
104.53 |
478*7 |
81.31 |
| DN500 |
---- |
---- |
---- |
---- |
530*9 |
115.62 |
529*7 |
90.11 |
| DN600 |
---- |
---- |
---- |
---- |
630*9 |
137.82 |
630*7 |
107.5 |
Our Advantages
Longitudinally welded pipes
The production process of straight seam welded pipe is simple, with high production efficiency, low cost, and rapid development. The strength of spiral welded pipes is generally higher than that of straight seam welded pipes. Narrow billets can be used to produce larger diameter welded pipes, and billets of the same width can also be used to produce welded pipes of different diameters. However, compared to straight seam pipes of the same length, the weld length increases by 30-100% and the production speed is lower. Therefore, smaller diameter welded pipes mostly use straight seam welding, while larger diameter welded pipes mostly use spiral welding.Straight seam welded pipes are divided into longitudinal submerged arc welding (LSAW) and electric resistance welding (ERW).
Square tube
Square tube is a term for square and rectangular pipes, which refers to steel pipes with equal sides. It is made of rolled steel strip after process treatment. Generally, the strip steel is unpacked, flattened, curled, and welded to form a circular tube, which is then rolled into a square tube and cut to the required length. Also known as square and rectangular cold formed hollow steel, abbreviated as square tube and rectangular tube, with codes F and J respectively. The allowable deviation of the wall thickness of rectangular pipes shall not exceed 10% of the nominal wall thickness when the wall thickness is not greater than 10mm, and shall not exceed 8% of the wall thickness when the wall thickness is greater than 10mm, except for the wall thickness of corner and weld areas. The typical delivery length of square tube is 4000mm-12000mm, with the majority being 6000mm and 12000mm.
SSAW spiral welded pipe
Spiral welded steel pipes refer to steel pipes with joints on the surface that are formed by bending and deforming steel strips or steel plates into circular or square shapes and then welding them. According to different welding methods, it can be divided into arc welded pipes, high-frequency or low-frequency resistance welded pipes, gas welded pipes, furnace welded pipes, Bondi pipes, etc. According to the shape of the weld seam, it can be divided into straight seam welded pipes and spiral welded pipes. Welded steel pipes are used in petroleum drilling and mechanical manufacturing industries. Furnace welded pipes can be used as water and gas pipes, and large-diameter straight seam welded pipes can be used for high-pressure oil and gas transportation, etc; Spiral welded pipes are used for oil and gas transportation, pipe piles, bridge piers, etc. Welded steel pipes have lower costs and higher production efficiency than seamless steel pipes.
Thick walled coiled tube
Thick walled coiled pipes, as the name suggests, are rolled out of steel plates. T-shaped welded pipes are the main type of coiled pipes, while spiral pipes and straight seam pipes are not strictly speaking coiled pipes. Before rolling pipes, it is necessary to familiarize oneself with technical requirements such as drawings, process material performance, etc., select an appropriate rolling machine, and determine whether to roll cold, warm, or hot. The specification and model range of hot-rolled thick walled steel pipes: diameter 400 to 3000mm, wall thickness 4 to 300mm, and length produced according to user needs. Products include: large coil tubes, large diameter thick wall coils, thick wall coils of various materials, hot rolled thick wall coils, cold rolled thick wall coils, etc.
Quality first: production and inspection in strict accordance with production standards;
Price advantage: discounts based on real market prices;
Transaction security: There will be no loss of customer funds;
After-sales guarantee: the customer's problem is our problem;
Long-term cooperation: quality assurance, price advantage, sincere service can last for a long time.
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Company Profile
Shandong Zhengde Metal Manufacturing Co., Ltd. is a production and sales company integrating hot-rolled steel coils, cold-rolled steel coils, galvanized steel coils, color-coated steel coils, section steel, steel pipes, steel wires, metal mesh, stainless steel, aluminum, copper and other metal products integrated large enterprises. Five production and sales bases have been formed in Binzhou, Liaocheng, Wuxi, Tianjin, Jinan and Tai'an, with more than 100 production lines, 4 nationally recognized laboratories, 2 technical engineering centers, and 5 enterprise technology centers. Products are exported to more than 50 countries and regions such as North America, South America, Europe, Africa, Oceania, Middle East, and Southeast Asia.
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