Duplex 2205 Stainless Steel Round Bars

High Strength (≥450 MPa Yield): Approximately twice the yield strength of 304/304L and 316/316L, allowing for smaller diameter shafts and reduced weight in high-load applications.

Superior Chloride SCC Resistance: Outstanding resistance to chloride-induced stress corrosion cracking, performing reliably in high-chlorine environments where 304L and 316L fail.

Excellent Pitting and Crevice Corrosion Resistance: PRE (Pitting Resistance Equivalent) ≥ 34 for S31803 and ≥ 35 for S32205, providing reliable service in seawater and aggressive chemical media.

Balanced Dual-Phase Microstructure: Approximately 50% ferrite and 50% austenite provides excellent combination of mechanical properties and corrosion resistance.

Good Machinability: Duplex 2205 has good machinability with proper tooling and speeds, suitable for turning, milling, drilling, and threading operations.

Excellent Weldability: Maintains balanced ferrite/austenite ratio in the weld zone with proper welding procedures using matching filler metals (ER2209).

Good Impact Toughness: Maintains good impact toughness down to -40°C, suitable for cold climate and offshore applications.

Low Thermal Expansion: Coefficient of thermal expansion (13.5 μm/m·K) lower than austenitic grades, reducing thermal stress in assemblies.

NACE MR0175 / ISO 15156 Compliant: Fully qualified for sour service applications.

International Certifications: Round bars can be certified by ABS, BV, DNV, LR, GL, RINA, CCS, KR, and NK, and comply with NORSOK M-650 standards.

S32205 is a restricted composition range of S31803, offering tighter control of Cr, Mo, and N to enhance corrosion resistance and ensure optimal phase balance. The PRE (Pitting Resistance Equivalent) for S32205 is ≥35, compared to ≤26 for 316L.

Comparison of Strength and Corrosion Resistance:

Impact Toughness (Charpy V-Notch, typical at -40°C):

Longitudinal: ≥ 60 J (typical)

Heat Treatment Condition:
Duplex 2205 stainless steel round bars are solution annealed at 1040–1120°C followed by rapid cooling (water quenching) . This heat treatment restores the balanced 40–60% ferrite / 40–60% austenite microstructure, dissolves unwanted intermetallic phases, relieves internal stresses, and ensures maximum corrosion resistance.

Critical Note: Unlike austenitic grades, Duplex 2205 requires water quenching after solution annealing. Air cooling may result in intermetallic phase precipitation, reducing corrosion resistance and toughness.

Delivery Condition Options:

l Black (Hot-Rolled): As-rolled with mill scale – for further processing

l Peeled/Turned: Smooth, bright surface – for precision machining

l Centerless Ground: Precision ground to tight tolerances – for shafting

Precision Ground Tolerances (Centerless Ground):

Standard Lengths:

l  Random Lengths: 3000mm – 6000mm

l  Fixed Lengths: 3000mm, 4000mm, 5000mm, 6000mm

l  Custom lengths available upon request

Straightness Tolerances:

*Formula: Weight (kg/m) = Diameter² (mm) × 0.00613 (based on density 7.80 g/cm³)*

Raw Material Selection: High-quality Duplex 2205 billets from certified mills (Outokumpu, Sandvik, POSCO, Baosteel) with certified chemical composition and ferrite/austenite balance.

Heating: Billets heated to a controlled temperature range (1150–1200°C) – lower than austenitic grades to prevent ferrite coarsening.

Hot Rolling: Heated billets passed through roughing and finishing stands to reduce diameter to required size.

Cooling: Controlled cooling to prevent intermetallic phase formation.

Solution Annealing: Critical heat treatment at 1040–1120°C to restore balanced duplex microstructure.

Water Quenching: Immediate water quenching after annealing (mandatory – air cooling unacceptable).

Pickling: Removal of oxides using specialized pickling acids for duplex grades.

Ferrite Content Measurement: Verification of phase balance – requirement: 35–65% ferrite.

Peeling/Turning (Optional): Removal of surface defects to produce bright finish.

Centerless Grinding (Optional): Precision grinding for tight tolerances.

Straightening: Roller straightening to ensure straightness tolerance.

Cutting: Cut to specified lengths.

Inspection & Testing: Dimensional check, PMI, ferrite measurement, mechanical testing.

Marking & Packing: Each bundle tagged with grade, heat number, dimensions, ferrite content.

Chemical Analysis: PMI verification for Cr, Ni, Mo, N (critical for duplex performance).

Ferrite Content Measurement: Magnetic induction method – requirement 35–65% ferrite documented.

Microstructure Examination: Verification of balanced dual-phase structure, absence of intermetallic phases (sigma, chi).

Mechanical Testing: Tensile strength (≥620 MPa), yield strength (≥450 MPa), elongation (≥25%), reduction of area (≥45%), hardness (≤290 HBW).

Charpy Impact Testing: Verification of low-temperature toughness at -40°C (upon request).

Dimensional Inspection: Diameter, length, straightness, roundness.

Surface Inspection: Visual check for surface defects, cracks, seams, and laps.

Ultrasonic Testing (UT): Per ASTM A388 for internal flaw detection (upon request).

Eddy Current Testing (ECT): For surface defect detection.

Pitting Corrosion Test: ASTM G48 upon request.

Third-Party Inspection: SGS, BV, DNV, TUV, LR, ABS available.

Offshore Platforms: Crane shafts, winch shafts, deck machinery shafts, mooring system components, riser connectors (ABS/BV/DNV/LR certified, NORSOK M-650 compliant).

Marine Propeller Shafts: Boat shafts, propeller shafts, rudder stocks, stern tube shafts, marine drive shafts, thrust shafts.

Pump Shafts: Seawater pump shafts, chemical pump shafts, desalination pump shafts, boiler feed pump shafts, centrifugal pump shafts, submersible pump shafts.

Fasteners: High-strength bolts, studs, nuts, threaded rods for offshore and marine service, sour service fasteners (NACE MR0175 compliant).

Valve Components: Valve stems, valve balls, valve spindles for high-pressure and corrosive service, actuator shafts, trim components.

Subsea Components: Subsea connector shafts, ROV components, subsea manifold pins, umbilical termination hardware.

Chemical Processing Shafts: Agitator shafts, mixer shafts, reactor components, heat exchanger tie rods, column internals for chloride service.

Desalination Equipment: High-pressure pump shafts, brine handling shafts, energy recovery device shafts.

Hydraulic Cylinder Rods: Piston rods, cylinder rods for offshore and marine hydraulic systems (centerless ground finish).

Precision Machined Parts: Turned components for subsea instrumentation, sensor housings, connector pins.

1. Why choose Duplex 2205 over 316L for round bars in marine environments?
Duplex 2205 offers approximately twice the yield strength (≥450 MPa vs ≥170 MPa) and superior chloride SCC resistance. For propeller shafts, pump shafts, and fasteners in seawater, Duplex 2205 provides reliable long-term performance.

2. What is the difference between S31803 and S32205 Duplex 2205 round bars?
S32205 has tighter composition controls (higher Cr, Mo, and N), providing enhanced corrosion resistance (PRE ≥35 vs ≥34). S32205 is generally preferred for new offshore construction and sour service applications.

3. Can Duplex 2205 round bars be machined?
Yes, Duplex 2205 has good machinability with proper tooling. Use carbide tooling, moderate speeds, and adequate coolant. For turning and milling, speeds should be 20-30% lower than for 316L.

4. Are Duplex 2205 round bars suitable for sour service (H₂S environments)?
Yes, Duplex 2205 is NACE MR0175 compliant for sour service applications. Hardness is controlled at ≤32 HRC. HIC and SSC test reports available upon request.

5. What is the maximum service temperature for Duplex 2205 round bars?
250°C (482°F) for continuous service in chloride environments; 300°C (572°F) for non-chloride service. Above 300°C, risk of sigma phase embrittlement.

6. What surface finish is best for hydraulic cylinder rods?
Centerless ground finish with h6 tolerance is recommended for hydraulic cylinder rods. This provides precise diameter (0.013mm tolerance for 10-30mm) and smooth surface finish (Ra 0.2-0.4μm).

7. Can Duplex 2205 round bars be welded?
Yes, but require proper welding procedures with low heat input and N₂ shielding gas. Matching filler metal ER2209 is recommended. Post-weld heat treatment generally not required.

High-Strength Material: 2.2-2.6x stronger than 316L – smaller diameters for same load

Marine & Offshore Certified: ABS, BV, DNV, LR certifications available

NORSOK M-650 Qualified: Complete documentation for offshore projects

NACE MR0175 Compliant: Full sour service certification

Ferrite Controlled: 35-65% ferrite documented per heat

Full Traceability: Heat number on each bundle – traceable to raw material

Complete Diameter Range: 10mm to 250mm – standard and custom sizes

Multiple Surface Finishes: Black, peeled, turned, ground – all available

Precision Tolerances: h6, h9, h11 – meet your requirements

Global Delivery: Exported to major offshore, marine, and subsea projects worldwide

Website: www.womicstainless.com

E-mail: info@womicstainless.com

Tel / WhatsApp / WeChat:

Victor: +86 15575100681

Jack: +86 18390957568

Womic Steel – Your reliable partner for high‑quality stainless steel products, precision machined components, and custom solutions for corrosion‑resistant applications.

Stock Examples (Duplex 2205 Stainless Steel Round Bars – Peeled Finish – Marine Grade):

Stock Examples (Duplex 2205 Stainless Steel Round Bars – Centerless Ground – High Precision):

Stock Examples (Duplex 2205 Stainless Steel Round Bars – Fastener Grade):

Related Keywords:

Duplex 2205 stainless steel round bar, S32205 high strength shafting, marine propeller shaft material, NACE MR0175 round bar, offshore platform shaft, seawater resistant round bar, ABS certified Duplex bar, DNV approved stainless steel bar, ferrite controlled round bar, pump shaft material 2205, chemical process shaft, subsea fastener bar, Duplex 2205 threaded rod, sour service bolt material, high yield strength stainless bar 450 MPa, Duplex stainless steel round bar weight chart, 2205 round bar for marine hardware, Duplex 2205 shaft for desalination pump, centerless ground Duplex bar h6 tolerance.