Kamal Steels is a leading Duplex Steel Manufacturer, Supplier, Stockist and Exporter in India offering a complete range of Duplex Steel Pipes, Duplex Steel Tubes, Super Duplex Pipes and Super Duplex Tubes for critical industrial applications. Our duplex steel products are manufactured according to international ASTM, ASME, EN and ISO standards and are widely used in oil & gas, offshore, marine, petrochemical, desalination, chemical processing and power generation industries.
Duplex stainless steel combines the advantages of both austenitic and ferritic stainless steels, providing superior corrosion resistance, excellent mechanical strength and exceptional durability in aggressive operating environments. As a trusted duplex steel supplier in India, we maintain extensive inventory in Duplex 2205, Duplex S31803, Duplex S32205, Super Duplex 2507 and Super Duplex S32760 grades to support industrial projects worldwide.
With decades of industry experience, competitive pricing, ready stock availability and worldwide export capabilities, Kamal Steels has established itself as a reliable source for duplex steel piping solutions across India, the Middle East, Europe, North America, Africa and Asia Pacific markets.
What is Duplex Steel?
Duplex steel is a stainless steel alloy consisting of a mixed austenitic-ferritic microstructure, typically containing roughly equal proportions of the two phases of austenitic and ferritic microstructures. This unique dual-phase structure provides significantly higher strength and better corrosion resistance than conventional stainless steel grades such as 304 and 316.
Duplex stainless steel is specifically designed for applications requiring resistance to pitting corrosion, crevice corrosion, stress corrosion cracking and chloride attack. Due to its outstanding mechanical properties and long service life, duplex steel has become one of the most preferred materials for critical piping systems and process equipment.
Duplex Steel Grades Available
Grade
UNS Number
W.Nr.
Description
Duplex 2205
UNS S31803
1.4462
Standard duplex grade with excellent corrosion resistance and high mechanical strength
Duplex 2205
UNS S32205
1.4462
Higher-alloyed 2205 composition with enhanced corrosion performance
Super Duplex 2507
UNS S32750
1.4410
High pitting and crevice corrosion resistance with excellent strength
Super Duplex 2507
UNS S32760
1.4501
High strength with excellent seawater and offshore service resistance
Duplex Steel vs Super Duplex Steel
Duplex and super duplex stainless steels are both two-phase stainless steels
that combine high mechanical strength with good corrosion resistance.
However, super duplex grades contain higher levels of alloying elements and
provide greater resistance to pitting, crevice corrosion and demanding
seawater environments than standard duplex grades such as 2205.
Property
Duplex 2205
Super Duplex 2507
Typical UNS
UNS S31803 / UNS S32205
UNS S32750 / UNS S32760
Corrosion Resistance
High
Very High
Strength
High
Very High
Pitting Resistance
High
Superior
Seawater Service
Suitable
Excellent
Typical Applications
Oil & Gas, Chemical Processing, Marine
Offshore, Desalination, Seawater Service
Duplex 2205 is commonly selected when a combination of high strength and
corrosion resistance is required at a balanced cost. Super Duplex 2507 is
generally preferred for more severe chloride-containing environments,
including seawater, offshore and desalination applications, where higher
pitting and crevice corrosion resistance is required. The final grade
selection should be based on the operating temperature, pressure, chloride
level, corrosion conditions and applicable project specification.
All duplex steel pipes and tubes supplied by Kamal Steels comply with internationally recognized ASTM specifications to ensure superior quality, reliability and performance in critical applications.
ASTM Standard
Description
ASTM A790
Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASTM A789
Seamless and Welded Ferritic/Austenitic Stainless Steel Tubes for General Service
Higher yield strength than many austenitic stainless steels such as 304/316
Excellent Corrosion Resistance
Superior protection against pitting and crevice corrosion
Stress Corrosion Resistance
Excellent performance in chloride-rich environments
Long Service Life
Reduced maintenance and replacement costs
Cost Efficiency
Allows thinner wall sections without sacrificing strength
High Temperature Performance
Reliable operation in demanding industrial conditions
Marine Resistance
Ideal for offshore and seawater applications
Frequently Asked Questions
Duplex steel is a stainless steel alloy containing both austenitic and ferritic microstructures, providing superior strength and corrosion resistance.
The most common grades are Duplex 2205 (UNS S31803/S32205) and Super Duplex 2507 (UNS S32750/S32760).
Super Duplex 2507 offers higher strength and better corrosion resistance than Duplex 2205, especially in seawater and offshore applications.
ASTM A790, ASTM A789, ASTM A928 and ASTM A815 are the primary standards used for duplex steel pipes, tubes and fittings.
We supply duplex steel seamless pipes, welded pipes, seamless tubes, welded tubes, instrumentation tubes, hydraulic tubes and heat exchanger tubes.
Duplex steel products are widely used in oil & gas, offshore, marine, petrochemical, desalination, power generation and chemical processing industries.
Yes, Mill Test Certificates, inspection reports and material traceability documents are available with supplied products, subject to the applicable order and inspection requirements.
Yes, Kamal Steels exports duplex steel pipes and tubes to customers across the Middle East, Europe, North America, Africa, Asia Pacific and other international markets.
Duplex 2205 can be suitable for many seawater and marine applications because of its high strength and good resistance to chloride-related corrosion. However, for more severe seawater, offshore and high-chloride environments, Super Duplex 2507 may be preferred due to its higher pitting and crevice corrosion resistance.
UNS S31803 and UNS S32205 are both associated with Duplex 2205 and have the same W.Nr. 1.4462 designation. UNS S32205 represents the higher-alloyed 2205 composition with tighter chemistry requirements, providing enhanced corrosion performance compared with the original UNS S31803 specification.
