Duplex Steel Flanges: Superior Performance and Wide-Ranging Industrial Connection Solutions
In harsh industrial environments, material selection often determines the success or failure of a project.
Duplex steel flanges, as critical connecting components in modern industrial piping systems, have become the preferred material in demanding industrial environments such as petrochemicals, seawater treatment, and papermaking due to their unique performance advantages. As a core product of the JIAJI Forging brand, we are committed to providing customers with high-performance duplex steel flange solutions.
This article comprehensively introduces the performance characteristics, application areas of duplex steel flanges, and how the JIAJI Forging brand ensures product reliability through strict quality control, assisting engineering design and procurement personnel in making wiser material choices.
01 Unique Performance Advantages of Duplex Steel Flanges
The reason duplex steel flanges can replace traditional stainless steel flanges in numerous industrial applications lies in their unique microstructure and chemical composition. These flanges are composed of a microstructure with approximately half ferrite and half austenite, combining the advantages of both to create exceptional performance unattainable with a single-phase structure.
In terms of chemical composition, duplex steel typically contains 18%-28% chromium and 3%-10% nickel, with some grades also containing alloying elements like molybdenum, copper, niobium, titanium, and nitrogen . The precise ratio of these elements gives duplex steel flanges unparalleled performance advantages.
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Exceptional Strength Characteristics: The yield strength of duplex steel flanges can reach 400-550 MPa, which is more than twice that of common austenitic stainless steel . This high strength allows for reduced flange thickness under the same pressure conditions, lowering material costs and weight while maintaining system integrity.
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Outstanding Corrosion Resistance: A particularly prominent advantage of duplex steel flanges is their excellent resistance to chloride stress corrosion cracking . In environments containing chlorides, traditional austenitic stainless steels are prone to stress corrosion cracking above 60°C, whereas duplex steel flanges maintain good resistance even under high-stress conditions.
Furthermore, duplex steel also exhibits excellent resistance to pitting, crevice corrosion, and corrosion fatigue . The pitting and crevice corrosion resistance of high-chromium duplex stainless steel containing 25% chromium even surpasses that of ordinary austenitic stainless steels.
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Good Weldability and Processability: Duplex steel flanges have a low hot cracking tendency, generally requiring no preheating before welding and no post-weld heat treatment . Compared to austenitic stainless steel, duplex steel has higher thermal conductivity and a lower coefficient of linear expansion, making it more suitable for applications like heat exchanger tube sheets .
02 Application Fields and Practical Value
Due to their exceptional performance characteristics, duplex steel flanges find extensive applications in various harsh industrial environments. These environments typically impose extremely high demands on the material’s corrosion resistance, strength, and reliability.
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Petrochemical and Oil & Gas Industry: In this sector, duplex steel flanges are used in various equipment such as transmission pipelines, pressure vessels, and heat exchangers . They effectively resist corrosion from media like hydrogen sulfide, carbon dioxide, and chlorides, ensuring long-term safe operation of the equipment.
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Seawater Treatment and Desalination Systems: The superior resistance of duplex steel flanges to chloride stress corrosion cracking makes them an ideal choice for seawater treatment systems . In desalination plants, they are used in key parts like high-pressure pipes, pump casings, and valves.
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Paper and Food Industries: The various chemicals and high-temperature environments in the papermaking process pose severe challenges to materials . Duplex steel flanges, with their good corrosion resistance and strength, become the preferred material for paper industry equipment. Similarly, they also play a significant role in food processing equipment.
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Environmental Protection and Energy Sectors: Duplex steel flanges also demonstrate excellent performance in flue gas desulfurization systems, wastewater treatment equipment, and the energy and environmental protection industries . They can resist corrosion from acidic media, ensuring the long-term stable operation of environmental protection facilities.
Using duplex steel flanges can extend the service life by four to five years compared to general stainless steel, significantly reducing product replacement costs and labor maintenance costs . Although the initial investment in duplex steel flanges may be higher than traditional stainless steel, their longer service life and lower maintenance requirements result in a significantly improved overall cost-effectiveness .
03 JIAJI Forging’s Quality Control and Brand Commitment
In the manufacturing field of duplex steel flanges, the JIAJI Forging brand always adheres to the principle of the highest quality standards. We deeply understand the significant impact of flange product reliability on the entire system’s safety under harsh working conditions.
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Rigorous Material Selection: We only select high-quality duplex steel materials, including famous grades such as 2205 (S31803/S32205), 2507 (S32750), and super duplex steel S32760 . Every incoming material undergoes strict spectroscopic analysis to ensure the chemical composition meets standard requirements, guaranteeing product quality from the source.
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Application of Advanced Manufacturing Processes: JIAJI Forging adopts the forging forming process to manufacture duplex steel flanges . Compared to the casting process, forging effectively refines the material grains, improving the mechanical properties and corrosion resistance of the flanges. We possess a complete production line, including advanced equipment for forging, pressing, machining, cold forming, hot extrusion, and heat treatment.
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Establishment of a Comprehensive Inspection System: We have introduced various precision testing equipment, including X-ray inspection, magnetic particle inspection, ultrasonic inspection, spectroscopic analysis, metallographic analysis, tensile testing, and hardness testing . These inspection methods ensure that every product leaving the factory meets international standards and customer requirements.
The duplex steel flanges of the JIAJI Forging brand are strictly produced in accordance with American standards (ASTM A182), Chinese national standards (GB/T), and other international standards (such as German standard DIN, European Union standard EN, etc.) . We are deeply aware that in critical applications, flange quality is related to the safe operation of the entire system, so we never compromise on quality.
Our duplex steel flange products cover various types, including slip-on flanges, welding neck flanges, blind flanges, and blind plates . Specifications range from DN15 to DN3600, and pressure classes range from PN0.25 to PN42, meeting the diverse needs of different customers .
With the continuous development of industrial technology and increasing demands on material performance, the application prospects of duplex steel flanges will be even broader. The JIAJI Forging brand will continue to adhere to the principle of guaranteed material quality and reputation first, providing customers with higher quality duplex steel flange products and technical support.
In future development, we will further optimize the product structure and develop new duplex steel materials more suitable for harsh working conditions, helping customers maintain competitiveness in severe industrial environments. Choosing JIAJI means choosing a reliable partner.