| After-sales Service: | Yes |
|---|---|
| Warranty: | Yes |
| Type: | Seamless |
| Technique: | Hot Rolled |
| Material: | Carbon Steel |
| Surface Treatment: | Black |
| Samples: |
|---|
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Audited Supplier GB 5310 20MnG Seamless steel tubes and pipes for high pressure boiler,Manufacture:Seamless process ,Hot-finished or Cold-finished,Wall thickness(WT): 2.8 mm--150 mm.Outer diameter (OD): 23 mm--1500 mm.
Standard:GB 5310
Seamless steel tubes and pipes for high pressure boiler.
GB 5310 standard is applicable to steam boilers and pipeline seamless pipes for the manufacture of high pressure and above.
GB 5310 20MnG Seamless steel tubes and pipes for high pressure boiler.
Manufacturing methods
(1)Steel smelting method
GB 5310 20MnG steel will be smelted by electric furnace plus furnace refining, oxygen converter plus furnace refining or electroslag remelting method.
(2)Manufacturing methods and requirements for tube blanks
The tube blank can be produced by continuous casting, die casting or hot rolling (forging).
(3)Manufacturing method of steel tube
GB 5310 20MnG Steel tubes shall be manufactured by hot rolling (extrusion, expansion) or cold drawing (rolling).
Heat treatment for GB 5310 20MnG High Pressure Boiler Tubes
| Grade | Heat treatment |
| 20MnG | 880 ºC~940 ºC,Normalizing |
| Steel Pipe | Chemical Composition(%) | |||||||||
| C | Si | Mn | Cr | Mo | V | Ni | Cu | P | ||
| Max | ||||||||||
| 20MnG | 0.17~0.23 | 0.17~0.37 | 0.70~1.00 | ≤0.25 | ≤0.15 | ≤0.08 | ≤0.25 | ≤0.20 | 0.025 | |
| Steel Pipe | Tensile properties | Impact energy(Akv),J | Hardness | |||||||
| Tensile strength (MPa) |
Yield Strength (MPa) |
Elongation % |
Portrait | Landscape | A | B | C | |||
| HBW | HV | HRC | ||||||||
| Portrait | Landscape | |||||||||
| Max | Min | |||||||||
| 20MnG | ≥415 | 240 | 22 | 20 | 40 | 27 | - | - | - | |
| Type of steel pipe | Outer diameter(mm) | Tolerance | |||
| ordinary | advanced | ||||
| Hot rolled tube | OD | ≤50 | ±0.40 | ±0.30 | |
| >50~≤325 | WT≤35 | ±0.75% | ±0.5% | ||
| WT>35 | ±1% | ±0.75% | |||
| >325 | ±1% | ±0.75% | |||
| WT | ≤4.0 | ±0.4 | ±0.3 | ||
| >4.0~≤20 | ±10% | ±7.5% | |||
| >20 | OD<219 | ±10% | ±7.5% | ||
| OD≥219 | +12.5% -10% |
±10% | |||
| Cold drawn tube | OD | ≤25.4 | ±0.15 | - |
| >25.4~≤40 | ±0.20 | - | ||
| >40~≤50 | ±0.25 | - | ||
| >50~≤60 | ±0.30 | - | ||
| >60 | ±0.5% | - | ||
| WT | ≤2.8 | ±0.2 | - | |
| >2.8 | ±7.5% | - |
1. Materials: Take the raw materials out of the raw material warehouse or procurement channels, and conduct inspection and sorting;
2. temperature control: according to the required performance of the product, choose the appropriate temperature, and control it within a certain range;
3. Heating: Use hot blast stove or other heating methods to heat raw materials to the required temperature;
4, annealing: the heated raw materials into the torch box for annealing treatment, in order to improve the mechanical properties of raw materials;
5. Hot rolling: Put the heated raw materials into the hot rolling mill, and process the raw materials through pressure to obtain the required products;
6. cooling: hot rolled products with water or other coolant for cooling, to ensure the stability of the product structure;
7. detection: physical and chemical performance test to determine whether it meets the requirements;
8. Finishing: Organize the products, label them, and prepare them for loading and delivery.
Testings
(1)Hydraulic test
The steel pipe shall be hydraulically tested one by one, and the eddy current testing can instead of the hydraulic test.
(2)Flattening test
Steel pipes with an outer diameter greater than 22 mm to 400 mm and a wall thickness not greater than 40 mm shall be subjected to a flattening test.
(3)Bending test
Steel pipes with an outer diameter greater than 400 mm or a wall
(4)Flaring test
The steel pipe with an outer diameter of not more than 76 mm and a wall thickness of not more than 8 mm can be used for the flare test.
(5)Low-power test
Steel pipes should be tested at low magnification. Visually visible white spots, inclusions, subcutaneous bubbles, tumbling and delamination are not allowed on the cross-section acid immersion test piece.
(6) Non-metallic inclusions
Steel pipes shall be tested for non-metallic inclusions.
(7)grain size
The finished steel pipe should be tested for grain size.
(8)Microstructure
The finished GB 5310 20MnG steel pipe of high-quality carbon structural steel shall be ferrite plus pearlite, and no superheated structure shall be allowed;
(9)Decarburization layer
Cold drawn (rolled) finished steel pipes with an outer diameter of not more than 76 mm shall be inspected for the total decarburization layer.
(10)Non-destructive testing
The steel pipe shall be ultrasonically inspected and tested in accordance with the provisions of GB/T 5777.
Surface quality
The inner and outer surfaces of steel pipes do not have cracks, folds, crusting, rolling and separation. These defects shall be completely removed and the depth of defect removal shall not exceed 10% of the wall thickness. The actual outer diameter and wall thickness of the defect removal shall not be less than the minimum allowable for the outer diameter and wall thickness.
Our company was established in 2012, is a comprehensive company integrating industry and trade. The company has successively won the honorary titles of provincial integrity enterprise and municipal excellent enterprise. We are mainly engaged in various metal related products. Such as pipes, pipe fittings, rods, coils, profiles, medium and heavy plates, narrow strips and other types of materials. The warehouse has a variety of products of different specifications and materials, and the capacity is maintained at 30,000-50,000 tons/month. Products are widely used in petroleum, chemical, electric power, coal, machinery, high and low pressure boiler tubes, hydraulic props, ships and other industries. We make full use of the advantages of self-operated export rights and enter the international market. Our customers are located in South Korea, Canada, Iran, Pakistan, Indonesia, Vietnam, South America and other countries, and we have offices in Indonesia and Vietnam. The quality of our products is enjoyed at home and abroad. high reputation. We adhere to the business philosophy of "integrity service, win-win cooperation, customer first", and provide one-stop steel solutions for global customers. Welcome friends from all over the world to visit our company. We are looking forward to establishing business relationships and personal friendships with you.
Q:How do you control quality?
A:Mill test certification is supplied with shipment,third party inspection is avaliable.
Q:What are the advantages of your company?
A:We have many professionals,technical personnel,more competitive prices and best after-sales service than other stainless steel companies
Q:How many coutries you already exported?
A:Exported to more than 50 countries mainly from Arab, Kuwait, Egypt, Turkey, Jordan, Brazil, India, Indonesia, Korea, etc
Q:Can you provide sample?
A:Small sample in store and can provide the sample for free.Customized samples will take about 5-7days.
Q:Why should you buy from us not from other suppliers?
A:Diversified products, direct supply from manufacturer.
Q:What is your terms of payment ?
A:we accept T/T ,L/C ,D/A,D/P, Western union, paypal ,The payment method can be negotiated by both parties according to the actual situation.
Please Please leave your enquiry in the message box at the bottom of the product page and click SEND, we will contact you as soon as possible!
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