DUPLEX STAINLESS STEEL PIPE

Founded in 2013, Yantai Xinbaoshang Materials Technology Co., Ltd.
China's leading duplex stainless steel pipe manufacturer and supplier

ABOUT DUPLEX STAINLESS STEEL PIPE

Duplex stainless steel 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 stainless steel pipe offers a unique combination of outstanding strength, corrosion resistance, ductility, and cost-effectiveness, especially at low temperatures. Due to its exceptional properties, duplex stainless steel pipe is suitable for multiple industries including oil and gas, chemical processing, and construction. Long-term, duplex stainless steel pipe reduces overall operational costs while delivering high performance, making it an increasingly vital and indispensable material choice across numerous industrial sectors.

Duplex stainless steel pipe

THE DIFFERENCE BETWEEN DUPLEX STAINLESS STEEL PIPE AND SUPER DUPLEX STAINLESS STEEL PIPE

  • DUPLEX STAINLESS STEEL PIPE
  • SUPER DUPLEX STAINLESS STEEL PIPE

Duplex stainless steel 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 stainless steel 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 stainless steel pipe, it remains an ideal choice for numerous industrial applications.

Super duplex stainless steel pipe is an enhanced version of duplex stainless steel 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.

OUR PRODUCT DIMENSIONS

This table provides detailed specifications for (super) duplex stainless steel pipe, including size ranges, lengths, and standards to meet diverse application requirements.

Outer Diameter Range6m – 1016m
Wall Thickness Range1mm – 65mm
Maximum Length1800mm
MaterialN08904(904L) , N08367 , S30432 , S31042
Executive standardASTM A312 , ASTM SA213 , ASTM SA269 , ASTM B673 , ASTM B674 , ASTM B677 , ASTM B675 , ASTM B676 , ASTM B690

ADVANTAGES OF DUPLEX STAINLESS STEEL PIPE

1. Strength: Duplex stainless steel pipe boasts approximately twice the strength of standard austenitic or ferritic stainless steel, delivering exceptional load-bearing capacity.

2. Toughness and Ductility: While duplex stainless steel 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 stainless steel 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 stainless steel 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 stainless steel 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 stainless steel pipe

Microstructure of duplex stainless steel pipe

(SUPER) DUPLEX STAINLESS STEEL PIPE CHEMICAL COMPOSITION AND MECHNICAL CHARACTER

TypeUNSChemical compositionMechanical property
C≤CrNiMoCuN≥ksi
(Mpa)
≥ksi
(Mpa)
Elongation
Low alloy typeS315000.0318.0-19.04.3-5.22.5-3.00.05-0.1092(630)64(440)30
S320010.0319.5-21.51.0-3.0≤0.60≤1.000.05-0.1790(620)65(450)25
S320030.0319.5-22.53.0-4.01.5-2.00.14-0.2090(620)65(450)25
S323040.0321.5-24.53.0-5.50.05-0.600.05-0.600.05-0.2087(600)58(400)25
Type in the alloyS318030.0321.0-23.04.5-6.52.5-3.50.08-0.2090(620)65(450)25
S322050.0322.0-23.04.5-6.53.0-3.50.14-0.2095(655)70(485)25
High alloy typeS325500.0424.0-27.04.5-6.52.9-3.91.5-2.50.10-0.25110(760)80(550)15
Super DssS327500.0324.0-26.06.0-8.03.0-5.00.24-0.32116(800)80(550)15
S327600.0524.0-26.06.0-8.03.0 -4.00.5-1.00.20-0.30109(750)80(550)25

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PRODUCTION AND PROCESSES

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.

Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer
Seamless steel pipe manufacturer

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WHY CHOOSE US ?

Our comprehensive supply chain system and robust resource integration capabilities form the core strengths of our customer service. Through strategic investments and deep partnerships, we have established a robust supply network with multiple premium manufacturers, creating a comprehensive system covering the full range of products including steel pipes, pipe fittings, flanges, and more. This enables you to source products of various specifications through a single point of contact, significantly saving time and coordination costs. Leveraging our deep insights into local markets and sustained procurement volumes, we deliver higher-quality products at comparable price points, helping you maintain a competitive edge in the marketplace.

Yantai Tianma Center
YANTAIPIPE Team
Group Photo with Clients
Processing and Delivery Capabilities

Processing and Delivery Capabilities

To ensure rapid delivery, we maintain three large-scale warehousing and processing facilities in Yantai, Shandong and Cangzhou, Hebei, with a year-round inventory of no less than 35,000 tons. We provide comprehensive pipeline processing services including cutting, beveling, and anti-corrosion treatment. Leveraging mature local industrial clusters and supporting infrastructure, we efficiently complete the entire process—from inventory allocation and custom fabrication to quality inspection and packaging/shipping—within one week, fully safeguarding your project schedule and supply security.

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High-Standard Quality Control

High-Standard Quality Control

Consistent product quality is the foundation upon which we have earned the long-term trust of numerous partners. We consistently prioritize product quality above all else, strictly adhering to international standards and contractual specifications. Every product is accompanied by a comprehensive quality inspection report. We can flexibly add customized testing items based on your specific requirements or arrange for on-site verification by third-party inspection agencies to ensure all delivered products fully meet your expectations and specifications.

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Technical Team and Overseas Sales Network

Technical Team and Overseas Sales Network

We maintain a 20-member professional technical support team providing round-the-clock services including technical consultation, customized solutions, product quotations, freight coordination, and after-sales support. To strengthen our overseas sales network, we have established international offices in Hong Kong, China; Bangkok, Thailand; and Kuala Lumpur, Malaysia. Our team members possess extensive industry experience and professional technical qualifications. Through continuous process optimization, we ensure rapid response and effective handling at every stage.

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BLOG AND NEWS

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    In pipeline systems for petrochemicals, water supply, food processing, and pharmaceuticals, we frequently encounter pipe schedule such as SCH40 and SCH40S.For those unfamiliar with them, SCH40 and SCH40S are very easy to confuse because they look nearly identical, differing only in the addition of an “S” after the “40.” SCH40S is considered superior to SCH40.Through this article, let’s explore the differences between SCH40 and SCH40S, providing you with a practical guide for selecting the appropriate pipe schedule.

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END CUSTOMERS

Our pipeline products and services have been extensively deployed in major global energy projects, serving numerous international energy giants. These include CNPC, Sinopec, Shell, Total, as well as national oil companies in Kuwait, Azerbaijan, Abu Dhabi, Qatar, Algeria, and Saudi Arabia. Whether you operate as an EPC contractor or a distributor agent, our products and services consistently meet your stringent standards.

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