ASTM / ASME / EN Certified

Duplex Steel Pipes & Tubes Manufacturer & Supplier in India

Unicorn Metal Industries is a premier Duplex Steel Pipes Manufacturer in India, engineering high-strength, corrosion-resistant piping for severe-service environments. Designed for chemical plants, offshore platforms, and marine facilities, our dual-phase alloys resist pitting, crevice corrosion, and stress corrosion cracking where standard austenitic stainless steels fail.

As a leading Duplex Steel Pipes Supplier in India, we secure mill-direct pricing on fully traceable, high-performance seamless and welded piping. Every order comes complete with technical documentation, including MTCs, NACE compliance, and Third-Party Inspection (TPI) reports tailored to your blueprints.

We stock certified Duplex Steel Pipes & Tubes in ASTM/ASME A790 specifications for high-pressure and high-chloride applications. Our ready inventory features UNS S31803 Duplex Steel Pipes and UNS S32205 Duplex Steel Pipes with complete heat traceability and mill test certificates to support your critical projects.

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1/2″ NB to 24″ NBSize Range

UNS S31803 / UNS S32205Available Grades

Seamless / Welded / FabricatedManufacturing Types

ASTM A790 Duplex Steel Pipes UNS S31803 and UNS S32205 stocked by Manufacturer in India

Datasheet

Technical Specifications for Duplex Steel Pipes & Tubes

Specification Parameter	Technical Details
Standard Specifications	ASTM A790 / ASME SA790, ASTM A815
Material Grades	UNS S31803, UNS S32205 (Werkstoff Nr. 1.4462 / Duplex 2205)
Outer Diameter (OD)	1/2" NB to 8" NB (Seamless), 6" NB to 24" NB (Welded / Fabricated)
Wall Thickness / Schedule	SCH 20, SCH 30, SCH 40, STD, SCH 80 (0.5 mm to 45 mm WT)
Form & Types	Seamless, Welded, Fabricated, Single Random, Double Random & Cut Lengths
Quality Documentation	MTC (EN 10204 3.1 / 3.2), NACE MR0175/MR0103, TPI Clearance

UNS S31803 & UNS S32205 Duplex Grade Selection

Choosing the right grade of Duplex Steel Pipes prevents localized corrosion and operational downtime. Unicorn Metal Industries supplies mill-certified, ready-to-ship stock tailored to your exact pressure and environmental requirements:

Feature / Parameter	UNS S31803 Duplex Steel	UNS S32205 Duplex Steel
Material Classification	Standard 2205 Duplex Stainless	Dual-Certified / Upgraded 2205 Duplex
Chromium (Cr) Range	22.0% – 23.0%	21.0% – 23.0% (Tighter melt control)
Molybdenum (Mo) Range	3.0% – 3.5%	2.5% – 3.5% (Optimized pitting control)
Nitrogen (N) Content	0.14% – 0.20%	0.08% – 0.20% (Enhanced weld zone stability)
Pitting Resistance (PREN)	31 – 33	34 – 36 (Superior localized pitting resistance)
Yield Strength (0.2% Offset)	550 MPa (80 ksi) Min	450–550 MPa (65–80 ksi) Min
Tensile Strength	800 MPa (116 ksi) Min	655–800 MPa (95–116 ksi) Min
Corrosion Performance	Excellent in general chloride environments	Higher resistance to pitting & crevice attack
Primary Industry Applications	Chemical processing, paper pulp digesters	Subsea pipelines, RO desalination, NACE sour service
Stock Availability	Standard seamless & welded sizes	High-volume ready stock, dual-certified

Selecting the correct grade prevents premature structural degradation and ensures full compliance with international safety standards. All available options can be custom-cut and supplied with complete heat traceability to meet your exact engineering requirements. As a leading Duplex Steel Pipes Manufacturer in India, all our products are custom-cut to size and delivered with full EN 10204 3.1 MTC heat traceability.

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Chemical Composition of UNS S31803 & UNS S32205 Pipes

SHEET 02

Element / Requirement	UNS S31803	UNS S32205
UNS Designation	S31803	S32205
Werkstoff Nr.	1.4462	1.4462
Carbon (%)	0.03 max	0.030 max
Manganese (%)	2.0 max	2.00 max
Phosphorus (Max %)	0.020 max	0.030 max
Sulfur (Max %)	0.030 max	0.020 max
Silicon (%)	1.0 max	1.00 max
Chromium (%)	22.0 – 23.0	21.0 – 23.0
Molybdenum (%)	3.0 – 3.5	2.5 – 3.5
Nickel (%)	4.5 – 6.5	4.5 – 6.5
Nitrogen (%)	0.14 – 0.20	0.08 – 0.20
Iron (Fe)	Balance	Balance

Mechanical Properties of UNS S31803 & UNS S32205 Pipes

SHEET 03

Property / Requirement	UNS S31803	UNS S32205
Tensile Strength, Min (ksi / MPa)	116 ksi / 800 MPa	95 ksi / 655–800 MPa
Yield Strength, Min (ksi / MPa)	80 ksi / 550 MPa	65 ksi / 450–550 MPa
Elongation (%)	15% min	25% min
Density (g/cm³ / lb/in³)	7.8 g/cm³	7.805 g/cm³ / 0.285 lb/in³
Melting Point	1350°C	1420–1465°C (2588–2669°F)

Applications

Practical Applications of Duplex Steel Pipes & Tubes

These high-performance dual-phase profiles resist stress corrosion cracking and extreme fluid pressure, making them ideal for heavy-duty process environments. They are widely implemented across several core sectors for critical infrastructure and industrial systems.

APP / 01

Chemical & Petrochemical Processing

UNS S31803 Duplex Steel Pipes used for acid handling lines, storage tanks, heat exchangers, and organic fluid transport.

APP / 02

Offshore Oil & Gas Infrastructure

UNS S32205 Duplex Steel Pipes essential in subsea flowlines, risers, manifold systems, and high-pressure gas processing.

APP / 03

Marine & Desalination Systems

UNS S32205 Duplex Steel Pipes preferred for high pitting resistance (PREN) in reverse osmosis (RO) high-pressure tubing and seawater intake piping.

APP / 04

Pulp & Paper Processing

UNS S31803 Duplex Steel Pipes applied in digesters, bleaching systems, and liquor piping networks.

Duplex Steel Pipes Industrial Applications

Quality Assurance

Quality Testing Protocols & Certified Credentials

To ensure complete reliability on site, our steel products undergo rigorous quality checks prior to dispatch:

Certificate / Test Type	Purpose & Safety Utility
ISO 9001:2015 Certification	Confirms strict, quality-controlled manufacturing processes throughout production.
EN 10204 3.1 Mill Test Report (MTC)	Verifies exact chemical breakdown and mechanical strength tests with complete heat code traceability.
Non-Destructive Testing (NDT)	Includes Hydrostatic testing and Eddy Current / Ultrasonic testing to ensure zero leaks or cracks.
NACE MR0175/MR0103 Compliance	Certifies suitability for sour service and corrosion resistance in harsh environments.
Government & Export Clearances	Fully compliant with Indian trade regulations and international export norms for unrestricted global deployment.

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FAQ

Frequently Asked Questions

What is Duplex steel pipe used for?

Duplex steel pipes are primarily used in high-chloride, highly corrosive environments like subsea oil & gas pipelines, desalination reverse osmosis (RO) systems, petrochemical processing lines, and marine seawater cooling loops.

What is the difference between UNS S31803 and UNS S32205?

UNS S32205 is an upgraded, higher-nitrogen dual-certified version of UNS S31803. While both fall under Duplex 2205, S32205 has tighter chemical control limits on Chromium, Molybdenum, and Nitrogen, providing enhanced corrosion resistance and higher mechanical strength.

What temperature can Duplex 2205 pipes withstand?

Duplex 2205 pipes are rated for continuous service between -50°C and 300°C (-58°F to 572°F). Exposure to temperatures above 300°C causes embrittlement due to the formation of microstructural sigma phases.

Can ASTM A790 duplex pipes be welded on site?

Yes. Duplex steel pipes support standard welding procedures when proper pre-heating and post-weld heat treatment (PWHT) parameters are followed. Correct welding technique is critical to maintain the dual-phase microstructure and corrosion resistance in the heat-affected zone.

Are seamless and welded duplex pipes different in corrosion performance?

Seamless duplex pipes offer uniform microstructure throughout with consistent corrosion resistance. Welded pipes, when properly fabricated with appropriate filler materials and PWHT, provide equivalent performance meeting ASTM A790 standards.

Why source directly from an Indian duplex steel pipe manufacturer?

Direct factory sourcing eliminates middleman markups, gives you access to custom cut lengths, and guarantees authentic mill test certificates with full heat traceability. You also benefit from rapid dispatch and direct technical support.

What documents are included with each shipment?

Every shipment includes EN 10204 3.1 Mill Test Reports (MTC) confirming chemical composition and mechanical properties, NACE compliance certifications where applicable, and Third-Party Inspection clearances for critical applications.