What is 1.4462 Stainless Steel?

1.4462 stainless steel, commonly known as Duplex 2205 or UNS S32205, is a ferritic-austenitic duplex stainless steel that combines the beneficial properties of both phases. It offers approximately twice the yield strength of standard austenitic stainless steels and excellent resistance to stress corrosion cracking, pitting, and crevice corrosion. This combination of high strength and superior corrosion resistance makes it ideal for demanding applications in chemical processing, oil and gas, marine environments, and pulp and paper industries.

 

This duplex grade is standardized under key international systems.

Standard	Equivalent Grade
EN (Europe)	1.4462
ASTM/AISI (USA)	2205, UNS S32205
JIS (Japan)	SUS329J3L
Common Name	Duplex 2205

Its balanced composition provides a roughly 50/50 ferritic-austenitic microstructure, optimizing both phases for performance.

Element	C	Si	Mn	P	S	Cr	Ni	Mo	N
Content (%)	≤ 0.03	≤ 1.0	≤ 2.0	≤ 0.035	≤ 0.02	21.0 - 23.0	4.5 - 6.5	2.5 - 3.5	0.10 - 0.22

It offers high strength along with good toughness and corrosion resistance.

Property	Yield Strength (Rp0.2)	Tensile Strength (Rm)	Elongation (A)	Hardness (HB)	Impact (J)
Typical Value	≥ 450 MPa	620 - 880 MPa	≥ 25%	≤ 293	≥ 100 (20°C)

 

Key Characteristics and Applications of 1.4462 / Duplex 2205

High Strength and Excellent Fatigue Resistance: The duplex structure provides high yield strength, allowing for thinner, lighter structures and components, reducing material costs and weight.

Outstanding Corrosion Resistance: Offers excellent resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC), especially in chloride environments, with PREN typically > 34.

Good Weldability: Can be welded using common techniques, though care must be taken to maintain the balanced microstructure in the weld and heat-affected zone.

Good Thermal Conductivity: Higher thermal conductivity than austenitic grades, beneficial for heat transfer applications.

 

Primary Applications:

Oil & Gas: Pressure vessels, pipelines, flowlines, heat exchangers, and offshore platform components.

Chemical & Petrochemical: Tanks, reactors, columns, and piping systems handling corrosive media including chlorides and acids.

Pulp & Paper Industry: Digesters, bleaching equipment, and handling systems for chloride-containing liquors.

Marine & Offshore: Seawater piping systems, propeller shafts, desalination plants, and marine hardware.

Pollution Control: FGD scrubbers, ducting, and chimney liners.

Structural Engineering: Bridges, storage tanks, and architectural features in corrosive environments.

 

How does Duplex 2205 (1.4462) compare to 316L (1.4404) in terms of performance?
Duplex 2205 offers approximately twice the yield strength of 316L (450 MPa vs. 200 MPa), providing significant weight-saving potential in structural designs and allowing for thinner wall sections in pressure-containing equipment. It also demonstrates superior resistance to stress corrosion cracking (SCC) in chloride environments, where 316L may fail. With a PREN of 34-35 vs. 316L's PREN of 24-26, 2205 offers better pitting and crevice corrosion resistance, making it suitable for more aggressive conditions. However, 316L has better formability and is more readily available in thin sections. The choice depends on specific application requirements, with 2205 selected where its higher strength and corrosion resistance justify the cost premium.

 

What are the key considerations when welding 1.4462 duplex stainless steel?
The primary goal is to preserve the balanced 50/50 ferrite-austenite microstructure in the weld and heat-affected zone to maintain corrosion resistance and mechanical properties. This requires using matching or over-alloyed filler metals (typically with higher nickel content), controlling heat input to avoid excessive ferrite formation or precipitation of brittle intermetallic phases, and ensuring proper shielding gas (typically Ar + 2-5% N2) to maintain nitrogen levels. Heat input should be controlled between 0.5-2.5 kJ/mm, with interpass temperature below 150°C. Post-weld cooling rate must be controlled, and the material should not be held in the critical temperature range (approx. 600-1000°C) for extended periods to avoid sigma phase formation.

 

Looking for a Reliable Supplier of 1.4462 / Duplex 2205 Stainless Steel?
GNEE Steel supplies high-quality Duplex 2205 (1.4462) stainless steel in plate, sheet, pipe, tube, bar, and fitting forms. We support your projects with comprehensive processing services including cutting, bending, and welding, and provide full material certification (EN 10204 3.1) to ensure compliance with international standards. If you have any requirements, please feel free to contact us.