DUPLEX STEEL SEAMLESS PIPE
Founded in 2013, Yantai Xinbaoshang Materials Technology Co., Ltd.
China's leading duplex steel seamless pipe manufacturer and supplier
Duplex steel seamless pipe is an alloy pipe featuring both austenitic and ferritic microstructures combined in nearly equal proportions. It is characterized by a high chromium content, typically ranging from 22% to 25%, significantly higher than traditional stainless steels (such as 304 or 316, with chromium content around 18%). This elevated chromium content confers superior toughness and enhanced resistance to pitting and crevice corrosion in chloride environments, delivering exceptional performance under demanding conditions like marine or chemical processing systems. Compared to other common stainless steels, duplex steel seamless pipe offers a unique combination of outstanding strength, corrosion resistance, ductility, and cost-effectiveness, especially at low temperatures. Due to its exceptional properties, duplex steel seamless pipe is suitable for multiple industries including oil and gas, chemical processing, and construction. Long-term, duplex steel seamless pipe reduces overall operational costs while delivering high performance, making it an increasingly vital and indispensable material choice across numerous industrial sectors.
Duplex steel seamless pipe is an alloy with a unique microstructure combining both austenitic and ferritic phases, typically each comprising about 50%. This material offers higher strength than traditional austenitic stainless steel while exhibiting excellent corrosion resistance in chloride environments. Typically containing 18% to 25% chromium, duplex steel seamless pipe finds extensive use in petroleum, natural gas, and chemical industries. Its favorable corrosion resistance and mechanical properties ensure reliable performance across diverse environments. While its capabilities under extreme corrosion conditions are relatively limited compared to super duplex steel seamless pipe, it remains an ideal choice for numerous industrial applications.
Super duplex steel seamless pipe is an enhanced version of duplex steel seamless pipe , containing higher proportions of alloying elements such as chromium, nickel, and molybdenum, typically with chromium content exceeding 25%. This material exhibits superior corrosion resistance and higher strength in extreme corrosive environments, making it suitable for withstanding greater pressures and loads. Super duplex steel seamless pipe finds extensive application in highly corrosive environments such as marine engineering, chemical processing equipment, and nuclear power. Its outstanding properties make it a critical material for demanding industries.
This table provides detailed specifications for (super) duplex steel seamless pipe, including size ranges, lengths, and standards to meet diverse application requirements.
| Outer Diameter Range | 6m – 1016m |
| Wall Thickness Range | 1mm – 65mm |
| Maximum Length | 1800mm |
| Material | N08904(904L) , N08367 , S30432 , S31042 |
| Executive standard | ASTM A312 , ASTM SA213 , ASTM SA269 , ASTM B673 , ASTM B674 , ASTM B677 , ASTM B675 , ASTM B676 , ASTM B690 |
1. Strength: Duplex steel seamless pipe boasts approximately twice the strength of standard austenitic or ferritic stainless steel, delivering exceptional load-bearing capacity.
2. Toughness and Ductility: While duplex steel seamless pipe feels less malleable than standard austenitic stainless steel, its toughness and ductility far surpass those of ferritic stainless steel.
3. Corrosion Resistance: Like all stainless steels, corrosion resistance primarily depends on composition, with chromium, molybdenum, and nitrogen content being most critical. Duplex steel seamless pipe exhibits exceptional corrosion resistance, demonstrating high resistance to stress corrosion cracking (SCC) even in chloride and sulfide environments. SCC is a corrosion phenomenon typically occurring when tensile stress, a corrosive environment, and elevated temperatures coincide.
4. Heat Resistance: Duplex steel seamless pipe exhibits higher thermal conductivity and a lower coefficient of thermal expansion than austenitic stainless steel. It can be safely used at temperatures as low as -50°C and demonstrates superior ductility at cryogenic temperatures compared to ferritic stainless steel.
5. Welding: Duplex steel seamless pipe generally exhibits good weldability and can be processed using all standard welding techniques, though welding difficulty is slightly higher compared to austenitic stainless steel.
Microstructure of duplex steel seamless pipe
| Type | UNS | Chemical composition | Mechanical property | |||||||
| C≤ | Cr | Ni | Mo | Cu | N | ≥ksi (Mpa) | ≥ksi (Mpa) | Elongation | ||
| Low alloy type | S31500 | 0.03 | 18.0-19.0 | 4.3-5.2 | 2.5-3.0 | 0.05-0.10 | 92(630) | 64(440) | 30 | |
| S32001 | 0.03 | 19.5-21.5 | 1.0-3.0 | ≤0.60 | ≤1.00 | 0.05-0.17 | 90(620) | 65(450) | 25 | |
| S32003 | 0.03 | 19.5-22.5 | 3.0-4.0 | 1.5-2.0 | 0.14-0.20 | 90(620) | 65(450) | 25 | ||
| S32304 | 0.03 | 21.5-24.5 | 3.0-5.5 | 0.05-0.60 | 0.05-0.60 | 0.05-0.20 | 87(600) | 58(400) | 25 | |
| Type in the alloy | S31803 | 0.03 | 21.0-23.0 | 4.5-6.5 | 2.5-3.5 | 0.08-0.20 | 90(620) | 65(450) | 25 | |
| S32205 | 0.03 | 22.0-23.0 | 4.5-6.5 | 3.0-3.5 | 0.14-0.20 | 95(655) | 70(485) | 25 | ||
| High alloy type | S32550 | 0.04 | 24.0-27.0 | 4.5-6.5 | 2.9-3.9 | 1.5-2.5 | 0.10-0.25 | 110(760) | 80(550) | 15 |
| Super Dss | S32750 | 0.03 | 24.0-26.0 | 6.0-8.0 | 3.0-5.0 | 0.24-0.32 | 116(800) | 80(550) | 15 | |
| S32760 | 0.05 | 24.0-26.0 | 6.0-8.0 | 3.0 -4.0 | 0.5-1.0 | 0.20-0.30 | 109(750) | 80(550) | 25 | |
We have two pipe product manufacturing bases in Yantai, Shandong Province. One of them, the General Pipe Manufacturing Base, has a history of nearly 70 years and is equipped with five hot-rolling production lines and one cold-drawing production line, with an annual production capacity of up to 500,000 tons. Leveraging our mature production processes and economies of scale, our product range encompasses over 1,000 specifications of pipe products, fully compliant with international standards such as API 5L, ASTM A106, and ASTM A333. While ensuring quality, we also offer a leading price advantage.
Our high-standard pipeline product production base has a stable production capacity of 800,000 tons, primarily producing high-grade steel products such as API 5L X100 PSL2, API 5CT Super 13Cr, and ASTM A335 P91. Our product specifications cover a wide range, with a maximum outer diameter of 20 inches, a wall thickness of up to 70 millimeters, and a single-piece length of up to 36 meters, capable of meeting the demands of steel pipes in various harsh operating conditions.
FAQs
We have no minimum order quantity requirements. Even if you only need one steel pipe or one pipe fitting, we can deliver on time and provide comprehensive services. Please note that certain high-grade steel products may require temporary production scheduling, which may result in minimum order quantity requirements. For specific details, please consult our sales team.
Of course, we provide free samples for products priced below $1,000. You only need to cover the shipping costs. For products priced above $1,000, please contact our sales team to discuss specific fees.
For products that are in stock, we will complete the final processing, quality inspection, packaging, and other steps within two weeks and deliver them as soon as possible according to the shipping schedule. For products that need to be ordered for production, an additional 2-3 weeks of production time will be required depending on the quantity requested.
In addition to providing factory warranty certificates, we can also provide test reports from internationally recognized quality testing agencies such as SGS, TUV, and DNV upon customer request. We are also available to assist third-party testing agencies with process inspections and final inspections prior to shipment.
Of course! Whether it's our own factory, processing plant, or our partners' factories, we welcome you to visit and exchange ideas at any time. If you need our assistance with visa matters, please feel free to contact our sales manager.
We are both a supplier and a manufacturer. We have three processing plants and warehouses, as well as a seamless steel pipe factory. We also collaborate closely with other outstanding steel pipe and pipe fitting factories in China, enabling us to offer a wide range of product specifications and a complete product system.
The delivery of the product is just the beginning of our service. If you encounter any issues during use, please feel free to contact our online customer service team at any time, and we will address the matter promptly. Additionally, we have offices in Hong Kong, Thailand, and Malaysia, enabling us to provide on-site technical support as needed.
Resource integration and supply chain capabilities are our core strengths. We offer a wide range of product specifications and numerous product types. At the same time, our inventory and processing capabilities ensure the fastest delivery times. We also provide professional customized solutions and comprehensive after-sales service.
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A comprehensive supply chain system and resource integration capabilities are our core strengths. By establishing long-term, in-depth partnerships with numerous outstanding factories, we have built a complete product system, ensuring that you can purchase all supporting products in one place, thereby saving a significant amount of time and cost. With our deep understanding of the local market and long-term, stable procurement volume, we are able to provide the highest quality products at the same price point, helping you maintain a competitive edge in the fiercely competitive market.
We have a professional team of more than 20 people and extensive experience in international projects. We can tailor solutions to your specific needs and provide quick quotes. We have three leading steel pipe product processing plants in Yantai, Shandong and Cangzhou, Hebei, which can meet all your deep processing and customization needs.
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Quality is our core principle. All products undergo comprehensive quality inspections before leaving the factory. After being stored in our warehouse, we conduct rigorous secondary quality inspections and can provide specified quality inspection plans according to customer requirements. We ensure that our product quality far exceeds contract standards and international standards.
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With a standing inventory capacity of 35,000 tons and a leading supply chain advantage, we achieve the fastest delivery times in the industry. We have offices in Hong Kong, Thailand, and Malaysia to ensure timely after-sales support for our customers. Our goal is to establish long-term partnerships with our customers, grow together, and create greater value.
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