Stainless Steel Duplex 2205

Duplex 2205 (S31803 / S32205) is a nitrogen-enhanced duplex stainless steel that consists of a microstructure of both austenite and ferrite (50/50 mix). This unique structure gives it twice the yield strength of 316L and significantly superior resistance to pitting and Stress Corrosion Cracking (SCC) in chloride environments. While it is a difficult material to machine due to its high strength and toughness, Jucheng Precision has the heavy-duty CNC equipment and technical expertise to process 2205 effectively. We are a trusted partner for the Oil & Gas and Desalination industries, delivering robust components that withstand the harshest marine and chemical conditions.

Back to Materials Get a Quote

Duplex 2205 Machining Capabilities

Capability	Technical Description	Jucheng Advantage
Heavy-Duty Turning	2205 is twice as strong as 316 and extremely tough. We use high-rigidity lathes with geared spindles to handle the high cutting forces.	Our capability to machine large diameter flanges and valve bodies (up to 800mm) ensures stability and chatter-free finishes.
Chip Control Strategies	Duplex produces strong, stringy chips that are hard to break. We utilize high-pressure coolant (70 bar) and specialized chip-breaking inserts.	Prevents chip wrapping and tool damage, allowing for automated production of critical oil & gas components.
Deep Hole Drilling	Drilling manifolds in 2205 requires specialized carbide drills to penetrate the work-hardened surface without seizing.	We successfully machine high-pressure fluid channels with precise straightness and surface finish.
Thread Milling	Cutting large API or NPT threads in Duplex using thread mills to minimize tool pressure and risk of tap breakage.	Ensures perfect thread profiles for high-pressure sealing applications where a stripped thread means a scrapped expensive part.

Fabrication Guidelines for Duplex 2205

Machinability Warning:
Duplex 2205 is significantly harder to machine than 316L. Cutting speeds must be reduced by ~20%, and tool life is shorter. Tip: Plan for higher machining costs due to increased cycle time and tooling consumption.

Work Hardening:
Like austenitic stainless, Duplex work-hardens, but more rapidly. Tip: Use aggressive feed rates and never let the tool dwell. “Babying” the cut will cause immediate surface hardening.

Stress Corrosion Resistance:
The primary reason to use 2205 is its resistance to Chloride Stress Corrosion Cracking (SCC), which causes 304/316 to fail in hot saltwater. Tip: Ideal for subsea or desalination equipment.

Primary Applications

Oil & Gas Industry
Subsea manifolds, Christmas tree valves, and downhole tools exposed to sour gas (H2S) and high pressure.

Desalination Plants
High-pressure pumps, reverse osmosis piping, and evaporators handling hot, concentrated brine.

Chemical Processing
Pressure vessels and heat exchangers handling aggressive chlorides and acids where 316L life is too short.

Pulp & Paper
Digesters and bleaching equipment requiring high strength and corrosion resistance.

Properties

Density	7.80 g/cm³
Tensile Strength	620 - 800 MPa
Yield Strength	450 MPa
Hardness	31 HRC (293 HB)
Elongation at Break	25%
Thermal Conductivity	19.0 W/m-K
PREN (Pitting Resistance)	35+
Machinability Rating	Low
Weldability	Good
SCC Resistance	Superior
Max Service Temp	300 °C
Max Part Size	2000 x 800 x 600 mm