2205 Duplex (UNS S32205/S31803) – Supplier of Round Bars, Seamless Tubes & Plates | Shanghai Hangbo Alloy Group
Date: 2026年7月22日 Categories: News Views: 246
By Shanghai Hangbo Alloy Group Co., Ltd. | ISO 9001:2015 Certified | Est. 2012 | Shanghai, China
Contact: sales@hangboalloy.com | hangbo@nickel-alloy.com | WhatsApp: +86 13611656360
Quick Answer: What Is 2205 Duplex?
2205 Duplex (UNS S32205 / S31803, W.Nr. 1.4462) is a nitrogen-enhanced duplex stainless steel with an approximately 50:50 austenite-ferrite microstructure that delivers twice the yield strength of standard 316L — typically ≥ 450 MPa (65 ksi) — plus superior resistance to chloride stress-corrosion cracking and pitting. It is specified to ASTM A240, A276, and A790 and extensively used in offshore oil & gas, chemical tankers, desalination, and marine structural applications. Shanghai Hangbo Alloy Group supplies 2205 Duplex as round bars, seamless tubes, and plates with full EN 10204 3.1 certification.
Industry Pain Point: Procurement teams routinely over-specify CRA (corrosion-resistant alloys) for moderate chloride service where 2205 Duplex — with its 2× strength advantage — cuts total installed cost by 25–40% versus 316L through thinner wall sections and reduced welding consumables, while eliminating the SCC failures that plague standard austenitics.
Key Properties at a Glance
| Property | Value |
|---|---|
| UNS Number | S32205 (preferred) / S31803 |
| W.Nr. | 1.4462 |
| Density | 7.805 g/cm³ (0.282 lb/in³) |
| Melting Range | 1420–1465°C (2590–2670°F) |
| Max Continuous Service Temp. | ~300°C (~572°F) |
| Tensile Strength (RT) | ≥ 655 MPa (95 ksi) |
| Yield Strength (RT) | ≥ 450 MPa (65 ksi) |
| Elongation (RT) | ≥ 25% |
| Hardness | ≤ 31 HRC / ≤ 293 HB |
| Thermal Conductivity (20°C) | 19 W/m·K |
| PREN (min) | 33–35 |
| Key Standards | ASTM A240, A276, A790, A789, A182, NACE MR0175 |
Product Overview
2205 Duplex Stainless Steel occupies the high-value intersection between two stainless families: it has the formability and toughness of austenitic grades (304/316L) combined with the high strength and chloride SCC resistance of ferritic stainless steels. The balanced duplex microstructure — roughly 50% austenite (FCC, for ductility) and 50% ferrite (BCC, for strength and SCC immunity) — is stabilized by deliberate nitrogen additions (0.14–0.20%) that also raise the Pitting Resistance Equivalent Number (PREN) into the 33–35 range.
Three numbers define the 2205 commercial proposition:
- 2× — yield strength versus 316L. This translates directly to thinner walls, lighter structures, and lower fabrication costs. A pressure vessel shell in 2205 can be 30–40% thinner than 316L at the same design pressure.
- 0 — chloride SCC susceptibility at temperatures where 316L cracks. The ferrite phase arrests SCC crack propagation, making 2205 the default choice for hot chloride environments up to ~150°C where stress-corrosion cracking is the dominant failure mode.
- −15% — lower coefficient of thermal expansion (13.0 vs. 16.0 μm/m·°C for 316L at 100°C), which reduces thermal fatigue risk in cyclic-service heat exchangers and eliminates the expansion-joint over-design that plagues austenitic piping systems.
Shanghai Hangbo Alloy Group supplies 2205 Duplex in round bars (Ø6–500 mm, solution-annealed and peeled), seamless tubes (OD 6–219 mm per ASTM A789), and plates (3–100 mm per ASTM A240) with complete mill test certification including ferrite content measurement (ASTM E562 point-count method) and ASTM A923 intermetallic phase verification.
Executive Standards
| Product Form | ASTM/ASME | EN | Additional |
|---|---|---|---|
| Plate, Sheet & Strip | ASTM A240 / ASME SA-240 | EN 10088-2 | ISO 15510 |
| Round Bar & Rod | ASTM A276 / A479 / ASME SA-276 | EN 10088-3 | NORSOK M-650 |
| Forgings (S31803) | ASTM A182 F51 / ASME SA-182 | EN 10088-3 | NORSOK M-650 |
| Forgings (S32205) | ASTM A182 F60 / ASME SA-182 | EN 10088-3 | — |
| Seamless Pipe | ASTM A790 / ASME SA-790 | EN 10216-5 | ISO 3183 |
| Seamless & Welded Tube | ASTM A789 / A249 / ASME SA-789 | EN 10216-5 | NACE TM0177 |
| Fittings | ASTM A815 / ASME SA-815 | — | MSS SP-43/SP-75 |
| Castings | ASTM A890 Gr. 4A (CD3MN) | EN 10283 | — |
| Sour Service | NACE MR0175 / ISO 15156 (≤232°C) | — | NORSOK M-001 |
Chemical Composition (wt.% per ASTM A240 – 100% OES Verified)
| Element | S32205 (Preferred) | S31803 (Legacy) | Role in 2205 Duplex |
|---|---|---|---|
| Chromium (Cr) | 22.0–23.0 | 21.0–23.0 | Passive film stability; primary pitting resistance contributor |
| Nickel (Ni) | 4.5–6.5 | 4.5–6.5 | Austenite stabilizer; controls phase balance |
| Molybdenum (Mo) | 3.0–3.5 | 2.5–3.5 | Critical pitting and crevice corrosion resistance in chlorides |
| Nitrogen (N) | 0.14–0.20 | 0.08–0.20 | Austenite stabilizer + strength enhancer; raises PREN; ensures HAZ re-austenitization after welding |
| Manganese (Mn) | ≤ 2.00 | ≤ 2.00 | Austenite stabilizer; deoxidizing agent |
| Silicon (Si) | ≤ 1.00 | ≤ 1.00 | Deoxidizer |
| Carbon (C) | ≤ 0.030 | ≤ 0.030 | Kept low to minimize carbide precipitation |
| Phosphorus (P) | ≤ 0.030 | ≤ 0.030 | Impurity control |
| Sulfur (S) | ≤ 0.020 | ≤ 0.020 | Minimized for hot workability |
| Iron (Fe) | Balance | Balance | Matrix |
Why S32205 supersedes S31803: S32205 mandates a higher nitrogen minimum (0.14% vs. 0.08%) and slightly tighter Cr/Mo ranges, ensuring that weld heat-affected zones re-form sufficient austenite for toughness and corrosion resistance. For any new specification, request UNS S32205 — the older S31803 designation is retained only for legacy replacement orders.
PREN: PREN = %Cr + 3.3 × %Mo + 16 × %N = 22.0 + 3.3 × 3.0 + 16 × 0.14 = 34.1 minimum. Typical mid-range S32205 achieves PREN 35–36.
Mechanical & Physical Properties
Room-Temperature Mechanical Properties (Solution-Annealed)
| Property | Value | Applicable Standard |
|---|---|---|
| Tensile Strength (Rm) | ≥ 655 MPa (95 ksi) | ASTM A240 |
| Yield Strength 0.2% (Rp0.2) | ≥ 450 MPa (65 ksi) | ASTM A240 |
| Elongation (A5, 50 mm) | ≥ 25% | ASTM A240 |
| Hardness | ≤ 31 HRC / ≤ 293 HBW | ASTM A240 |
| Impact Toughness (Charpy-V, −46°C) | ≥ 45 J (transverse) | ASTM A923 |
| Young's Modulus | 200 GPa (29.0 × 10³ ksi) | — |
| Shear Modulus | 77 GPa | — |
| Poisson's Ratio | 0.30 | — |
Elevated-Temperature Tensile Properties (Typical, Longitudinal)
| Temperature | Tensile Strength (MPa) | Yield Strength (MPa) | Elongation (%) |
|---|---|---|---|
| 20°C (68°F) | 720 | 520 | 30 |
| 100°C (212°F) | 650 | 430 | 30 |
| 200°C (392°F) | 590 | 370 | 28 |
| 300°C (572°F) | 560 | 340 | 25 |
Important Design Constraint: 2205 Duplex is NOT rated for sustained service above approximately 300°C (572°F). Long-term exposure in the 280–350°C range triggers "475°C embrittlement" (alpha-prime phase precipitation in ferrite), causing a catastrophic loss of room-temperature toughness. For applications above 300°C, consider a nickel-based alloy or a solid-solution-strengthened austenitic grade.
Physical Properties
| Property | at 20°C | at 100°C | at 200°C | at 300°C | Unit |
|---|---|---|---|---|---|
| Density | 7.805 | — | — | — | g/cm³ |
| Thermal Conductivity | 19 | 19 | 20 | 21 | W/m·K |
| Specific Heat | 480 | 500 | 530 | 560 | J/kg·K |
| Electrical Resistivity | 0.82 | 0.90 | 1.00 | 1.10 | μΩ·m |
| Mean Thermal Expansion (20°C–T) | — | 13.0 | 13.5 | 14.0 | μm/m·°C |
| Magnetic Permeability (μᵣ) | ~40 (ferrite phase) | — | — | — | — |
Thermal conductivity advantage: At 19 W/m·K, 2205 conducts heat approximately 30% better than 316L (14–15 W/m·K), which translates to smaller heat exchanger surface area requirements — a direct capital cost saving that compound with the thinner-wall strength advantage.
Heat Treatment
Solution Annealing — The Only Authorized Heat Treatment
| Parameter | Specification |
|---|---|
| Temperature | 1020–1100°C (1870–2010°F) |
| Soak Time | Minimum 1 hour per 25 mm section thickness; minimum 30 min for sections ≤ 10 mm |
| Cooling Method | Rapid water quench — MANDATORY. Air cooling is NEVER acceptable for section thickness ≥ 3 mm. |
| Target Cooling Rate | Exit 600°C (1110°F) within 3 minutes |
Why the quench is non-negotiable: The temperature window 600–950°C (1110–1740°F) is where catastrophic intermetallic phases — sigma (σ), chi (χ), and Cr₂N nitrides — precipitate in the ferrite phase at rates measured in seconds to minutes (not hours). Sigma phase, an Fe-Cr-Mo intermetallic, is the most dangerous: even 0.5% sigma volume fraction drops Charpy impact toughness from >100 J to <10 J and creates a continuous chromium-depleted zone that destroys pitting resistance.
A practical shop-floor test: after annealing, the material surface must be visibly free of a bluish or straw-colored oxide tint — these discoloration colors indicate a cooling rate slow enough to have passed through the sigma-nucleation window with detrimental effect.
Sensitization & Embrittlement Bands
| Mechanism | Temperature Range | Time to Damage | Consequence |
|---|---|---|---|
| 475°C Embrittlement (α') | 280–500°C | Hours to days | Loss of RT ductility/toughness |
| Sigma / Chi Formation | 600–950°C | Seconds to minutes | Total loss of toughness + pitting resistance |
| Carbide Precipitation (M₂₃C₆) | 450–850°C | Minutes to hours | Intergranular corrosion |
Fabricator guidance: Post-weld solution annealing is not required for most 2205 applications when correct welding parameters are followed. However, for severe forming (cold-reduction >20%) or after hot forming operations, re-solution-anneal the part per the 1020–1100°C water-quench schedule.
Production Process
1. Round Bars & Forgings
- Melting: AOD (Argon Oxygen Decarburization) or VOD (Vacuum Oxygen Decarburization) primary melt. Nitrogen is precisely metered into the AOD vessel to achieve the 0.14–0.20% target — this is the single most critical chemistry control point because nitrogen determines both strength and HAZ re-austenitization capacity.
- Hot Forging / Rolling: Billet reheated to 1150–1200°C (2100–2190°F), forged/hot-rolled with a minimum reduction ratio of 4:1. Finishing temperature maintained above 950°C to prevent sigma formation during deformation. Overheating above 1250°C increases ferrite fraction beyond 60% and risks hot shortness.
- Solution Annealing: 1020–1100°C with immediate water quench; quench-tank agitation is maintained for bars ≥ Ø50 mm to ensure the core exits the sigma-nucleation window within 3 minutes.
- Straightening, UT & Finishing: Multi-roll straightening to ≤ 0.5 mm/m deviation. 100% ultrasonic testing per ASTM A388 / EN 10308 on bars ≥ Ø50 mm. PMI on every bar. Ferrite content verified on sample pieces per ASTM E562 (target: 35–55% ferrite) or by magnetic ferrite scope per AWS A4.2 (target: FN 30–60).
2. Seamless Tubes & Pipes
- Hollow Preparation: Hot-pierced or hot-extruded from annealed billet at 1150–1200°C.
- Cold Pilgering / Cold Drawing: Multi-pass cold reduction (typically 40–60% total) with intermediate full solution anneals between passes. Each intermediate anneal: 1020–1100°C + water quench.
- Final Solution Anneal: Bright anneal at 1040–1080°C in hydrogen or cracked ammonia atmosphere (for tubes ≤ OD 50 mm) to preserve a clean, oxide-free surface finish suitable for direct installation.
- Testing: 100% hydrostatic or eddy current per ASTM E426 / A450. Destructive mechanical testing per heat: tensile, hardness, Charpy-V impact (at −46°C for NORSOK-qualified material), and ASTM A923 Method C corrosion test for intermetallic phase detection. ASTM G48 Method A pitting test (22°C, 24 hours) available on request.
3. Plates, Sheets & Strips
- Slab Preparation: Continuously cast slab with surface grinding to remove segregation zones. Hot rolling at 1150–1200°C starting temperature with finishing temperature ≥ 950°C.
- Solution Annealing: 1020–1100°C in a continuous roller-hearth furnace or batch furnace, immediate water quench. Roller-hearth lines allow superior quench uniformity compared to batch furnaces for thin-gauge sheet.
- Leveling & Cutting: Precision leveling to ≤ 3 mm/m flatness. Plasma, laser, abrasive waterjet, or shear cutting to final dimensions.
- Surface & NDE: Pickling + passivation per ASTM A380 (nitric-hydrofluoric acid pickle removes quench scale and chromium-depleted surface layer). 100% visual inspection. Ultrasonic testing per ASTM A435/A577 on request. ASTM A923 Method C corrosion verification on sample coupons from each heat-treatment lot.
Industry Applications
| Industry | Typical Components | Why 2205 Duplex? |
|---|---|---|
| Offshore Oil & Gas | Flowlines, manifolds, subsea umbilicals, seawater lift pipes, firewater systems | NACE MR0175 compliance; 2× strength of 316L cuts wall thickness/weight; SCC immunity eliminates CRA over-specification |
| Chemical Tankers & Cargo Tanks | Chemical cargo tanks, deck piping, heating coils | Resists 65%+ of IBC Code chemical cargoes; lighter tank structure reduces fuel cost per voyage |
| Desalination (SWRO/MED) | High-pressure brine piping, evaporator shells, reject headers | Chloride pitting resistance to 35,000+ ppm at 40–60°C; thinner walls = reduced pump energy for high-pressure RO trains |
| Pulp & Paper | Digesters, bleach plant washers, filtrate piping | Resistance to acid-chloride mixtures; high strength allows retrofitting into existing structural envelopes without reinforcement |
| Bridges & Civil Structures | Stay cables, reinforcement bar, bridge bearings | 100-year design life without coating maintenance; 2× yield of carbon-steel rebar eliminates congested reinforcement cages |
| Heat Exchangers & Pressure Vessels | Shells, tubesheets, baffles, tube bundles | 30% higher thermal conductivity than 316L + thinner-wall design strength → ~40% smaller heat exchanger footprint for equivalent duty |
Quality Assurance: 7-Stage Zero-Defect Inspection
- Raw Material & Melt Control: Incoming FeCr, Ni, and FeMo verified by OES (ASTM E1086) before charging. AOD nitrogen content verified by inert gas fusion (ASTM E1019) at tap. Only AOD/VOD-melted heats accepted — air-melt 2205 is categorically rejected due to uncontrolled nitrogen pickup risks.
- Phase Balance Verification: Ferrite content measured on-as-cast samples per ASTM E562 (point-count metallography) or calibrated magnetic ferrite scope (AWS A4.2). Acceptable range: 35–55% ferrite by volume. Material outside this band is fully remelted — no dilution blending permitted.
- Hot Working Surveillance: Infrared pyrometry on forging/rolling operations with ±10°C traceable calibration. Temperature excursions above 1250°C or below 950°C during hot deformation trigger automatic lot quarantine.
- Solution Anneal Integrity Check: Every lot is hardness-tested (HRC) as a rapid conformity check — hardness > 31 HRC triggers a full metallographic examination and ASTM A923 Method C corrosion test. Digital furnace charts archived with ±5°C accuracy.
- Destructive Mechanical Testing (Per Heat & Lot): Room-temperature tensile per ASTM A370 / ISO 6892-1. Charpy-V impact at −46°C (−50°F) per ASTM A370 for NORSOK-qualified product. ASTM A923 Method C (corrosion test for detrimental intermetallic phases) — mandatory for any lot with hardness > 28 HRC or where furnace chart shows quench delay > 90 seconds.
- Non-Destructive Examination: 100% ultrasonic testing per ASTM A388 (bars ≥ Ø50 mm) / ASTM A435 (plates ≥ 10 mm). 100% eddy current or hydrostatic testing (tubes). PMI (XRF + nitrogen analyzer or portable OES) on every finished piece.
- Documentation & Third-Party Release: EN 10204 Type 3.1 Mill Test Certificate with full chemistry, tensile/impact results, ferrite content measurement, and NDE summary. Third-party witness/inspection by SGS, Bureau Veritas, TÜV Rheinland, DNV, ABS, or Lloyd's Register available at no coordination surcharge.
Frequently Asked Questions
Q1: What is 2205 Duplex used for?
2205 Duplex is the workhorse alloy for chloride-containing environments where 316L fails from pitting or stress-corrosion cracking (SCC). Principal applications include offshore oil & gas flowlines and manifolds (NACE MR0175 sour service), chemical tanker cargo containment, desalination brine piping and evaporators, pulp mill bleach plants, bridge stay cables, and heat exchangers handling brackish or seawater cooling media. It is selected whenever the combined requirements are: (a) chlorides above 1000 ppm, (b) design stress that would over-thicken 316L, and (c) service temperature below 300°C.
Q2: What is the density of 2205 Duplex?
7.805 g/cm³ (0.282 lb/in³) at 20°C. This is approximately 2.5% lighter than standard austenitic grades (316L = 8.0 g/cm³), a consequence of the ~50% ferrite (BCC, lower atomic packing density) in the microstructure. Weight estimation formula for procurement: Mass (kg) = 7.805 × Volume (cm³) ÷ 1000.
Q3: What is the maximum service temperature of 2205 Duplex?
Approximately 300°C (572°F) for continuous service. The limiting factor is 475°C embrittlement — exposure in the 280–500°C range causes alpha-prime (α') phase precipitation within the ferrite grains, leading to progressive loss of room-temperature ductility and impact toughness. For applications with operating temperatures above 250°C that also require cold-start toughness (e.g., shutdown/startup cycling), specify Charpy impact testing at the minimum design metal temperature as a mandatory acceptance criterion.
Q4: What is the melting point of 2205 Duplex?
The melting range is 1420–1465°C (2590–2670°F). This is approximately 50–80°C higher than standard austenitic grades (316L = 1370–1400°C) because the ferrite phase has a higher solidus temperature. The practical implication for fabrication: preheat is never required for welding (ambient to 150°C interpass), and the higher melting range slightly reduces susceptibility to solidification cracking compared to fully austenitic grades.
Q5: What is the tensile strength of 2205 Duplex?
Minimum 655 MPa (95 ksi) per ASTM A240 in the solution-annealed condition. Typical values from production heats range 700–800 MPa. This represents approximately a 26% advantage over 316L (≥ 515 MPa). The nitrogen content (0.14–0.20%) is the primary contributor to this strength increase via interstitial solid-solution strengthening.
Q6: What is the yield strength of 2205 Duplex?
Minimum 0.2% offset yield strength is 450 MPa (65 ksi) per ASTM A240. This is the defining commercial advantage: more than double the 205 MPa (30 ksi) minimum yield of 316L. The yield advantage comes primarily from the BCC ferrite phase (which has inherently higher yield strength than FCC austenite) and secondarily from nitrogen solid-solution strengthening. In practical design terms per ASME Section VIII Div.1, a 2205 pressure vessel shell can be 30–40% thinner than a 316L shell at identical design pressure, delivering proportional reductions in weight, welding consumables, and material cost.
Q7: What is the elongation of 2205 Duplex?
Minimum elongation (A5, 50 mm gauge length) is 25% per ASTM A240. Typical values are 28–35%. While this is lower than 316L (≥ 40%), it is more than adequate for all standard forming operations — 2205 can be cold-bent, flared, expanded, and pressed. Minimum bend radius for cold forming: 2× thickness for plate and 3× OD for tube (vs. 1.5× and 2.5× respectively for 316L). The lower elongation reflects the BCC ferrite phase, which has fewer active slip systems than FCC austenite.
Q8: What are the full mechanical properties of 2205 Duplex?
In the solution-annealed condition per ASTM A240: tensile strength ≥ 655 MPa (95 ksi); yield strength ≥ 450 MPa (65 ksi); elongation ≥ 25%; hardness ≤ 31 HRC / ≤ 293 HBW. For NORSOK-qualified material (M-650), additional requirements include: Charpy-V impact ≥ 45 J average (single minimum 35 J) at −46°C in the transverse direction; ASTM A923 Method C pass (corrosion rate ≤ 10 mdd at 25°C); and ferrite content 35–55% per ASTM E562. Elevated-temperature properties degrade progressively — at 300°C, typical tensile is ~560 MPa with yield ~340 MPa.
Q9: What heat treatment does 2205 Duplex require?
Solution annealing at 1020–1100°C (1870–2010°F) with mandatory rapid water quenching. Air cooling is never permissible for section thicknesses ≥ 3 mm. The solution anneal dissolves all secondary phases (sigma, chi, Cr₂N, M₂₃C₆) and restores the correct austenite-ferrite phase balance. No subsequent aging or precipitation-hardening treatments apply — 2205 is not a precipitation-hardening grade. Post-weld solution annealing is required only for severe forming (>20% cold reduction) or hot forming that may have precipitated sigma. Most welded fabrications in 2205 go into service in the as-welded condition without PWHT.
Q10: What is the solution annealing temperature for 2205 Duplex?
1020–1100°C (1870–2010°F). The lower bound (1020°C) is set by the need to fully dissolve all sigma phase; the upper bound (1100°C) prevents excessive grain growth and a ferrite fraction exceeding 60%, which would reduce toughness. The quench must be sufficiently rapid that the material exits the 600–950°C sigma-nucleation window within 3 minutes. Any delay in the quench — stuck conveyor, insufficient water flow, batch stacking that shields the center of a plate stack — produces sigma phase that can reduce Charpy energy to single-digit joules.
Q11: How does 2205 Duplex compare to 316L?
| Property | 2205 Duplex | 316L | Advantage |
|---|---|---|---|
| Yield Strength | ≥ 450 MPa | ≥ 205 MPa | 2.2× — thinner walls, less weight |
| Tensile Strength | ≥ 655 MPa | ≥ 515 MPa | 1.3× |
| Elongation | ≥ 25% | ≥ 40% | 316L is more formable |
| PREN | 33–35 | ~24 | 50% higher — wider chloride envelope |
| Cl-SCC Resistance | Immune ≤150°C | Susceptible ≥ 60°C | Critical FAILURE difference |
| Thermal Conductivity | 19 W/m·K | 14.5 W/m·K | 30% better — smaller HX footprint |
| Thermal Expansion | 13.0 μm/m·°C | 16.0 μm/m·°C | Lower — reduced thermal stress |
| Density | 7.805 g/cm³ | 8.0 g/cm³ | ~2.5% lighter |
| Max Service Temp | ~300°C | ~800°C | 316L wins for high-temp service |
| Approx. Cost Premium | — | — | 1.8–2.5× baseline |
The decision rule: If your failure mode is pitting or chloride SCC at temperatures above 60°C, 316L is the wrong material — switch to 2205. If your service temperature exceeds 300°C, switch from 2205 to a solid-solution nickel alloy.
Q12: What is the price of 2205 Duplex per kg?
Indicative EXW pricing for 2205 Duplex round bars (Ø20–200 mm) ranges \$12–20/kg, with plates typically 5–10% lower and seamless tubes 15–25% higher. This positions 2205 at roughly 1.8–2.5× the cost of 316L — but the 2.2× strength advantage means the cost-per-unit-strength is actually equal to or lower than 316L. Volume orders (per-ton quantities) and mill-contract pricing can achieve the lower end. Shanghai Hangbo Alloy Group provides firm CIF/FOB quotations within 2 business hours — email sales@hangboalloy.com with your dimensions, quantity, and delivery destination.
Q13: Is 2205 Duplex weldable?
Yes, with appropriate procedures. Qualified processes: GTAW (TIG), GMAW (MIG), SMAW (stick), SAW, and FCAW. Recommended filler metal: ER2209 (AWS A5.9) / E2209 (AWS A5.4) — this over-alloyed filler (typically +2–3% Ni vs. base metal) ensures the as-deposited weld metal achieves 35–55% ferrite and adequate toughness. Key parameters: no preheat required; interpass temperature ≤ 150°C (300°F); heat input 0.5–2.5 kJ/mm; shielding gas for GTAW: Ar + 2% N₂ (nitrogen addition compensates for nitrogen loss from the weld pool). ER2209 filler can also be used for dissimilar welding of 2205 to carbon steel or 316L. Post-weld solution annealing is generally NOT required when these parameters are followed.
Q14: What product forms does Shanghai Hangbo supply for 2205 Duplex?
We supply 2205 Duplex in round bars (Ø6–500 mm, hot-rolled, forged, or cold-drawn), seamless tubes (OD 6–219 mm, wall 0.8–30 mm, per ASTM A789), seamless pipes (OD up to 610 mm, per ASTM A790), plates (3–100 mm thick, up to 2500 mm width), forgings (discs, rings, blocks per ASTM A182 F51/F60), welded pipes (OD up to 1219 mm), and fittings (elbows, tees, reducers, flanges per ASTM A815). Surface finishes include: black, pickled & passivated (ASTM A380), bright annealed (tubes), polished (180–600 grit), and machined.
Q15: Does Shanghai Hangbo ship internationally?
Yes. We export 2205 Duplex to over 40 countries with delivery terms: FOB Shanghai, CIF, CFR, DAP, and DDP (established accounts). Standard destinations include USA, Germany, UK, UAE, Saudi Arabia, Singapore, South Korea, Australia, and Brazil. Stock items ship within 2–4 weeks; mill-order production is 6–10 weeks. Air freight available for urgent ≤ 500 kg shipments. All export packages include: commercial invoice, packing list, certificate of origin (Form E / CO), EN 10204 3.1 MTC, and third-party inspection report (if requested).
Q16: What is the difference between S32205 and S31803?
S32205 is the preferred specification for all new orders. The key differences: S32205 mandates a higher minimum nitrogen content (0.14% vs. 0.08% for S31803), tighter chromium (22.0–23.0% vs. 21.0–23.0%), and tighter molybdenum (3.0–3.5% vs. 2.5–3.5%). These tighter ranges with higher nitrogen minimum ensure that weld HAZ regions consistently re-form ≥ 25% austenite — the threshold for adequate toughness and corrosion resistance. Purchasing rule: always specify UNS S32205 for new construction; accept S31803 only for legacy component replacement where the original material specification must be matched exactly.
Q17: Is 2205 Duplex magnetic?
Yes — magnetic, with a relative permeability (μᵣ) of approximately 30–50. The ferrite phase (~50% of the microstructure) is BCC iron, which is ferromagnetic at room temperature. This makes 2205 suitable for magnetic particle inspection (MPI) for surface crack detection — a non-destructive testing option not available for fully austenitic grades like 316L or 254SMO. The magnetic response also means 2205 components will attract a permanent magnet, which distinguishes them from austenitic stainlesses during PMI sorting. For applications where non-magnetic material is mandatory (e.g., MRI equipment, degaussing-sensitive naval systems), 2205 is NOT suitable — specify a fully austenitic grade with μᵣ ≤ 1.005 instead.
Contact Shanghai Hangbo Alloy Group
| Channel | Details |
|---|---|
| Company | Shanghai Hangbo Alloy Group Co., Ltd. (宝昭实业（上海）有限公司) |
| Website | www.nickel-alloy.com |
| Email (Sales) | sales@hangboalloy.com |
| Email (Technical) | hangbo@nickel-alloy.com |
| +86 13611656360 | |
| Skype | live:specialalloy001 |
| Address | Room 1508, No. 288 Shiyi Road, Baoshan District, Shanghai 200940, China |
| ISO Certification | ISO 9001:2015 — View certificate on request |
| Response Time | ≤ 10 minutes during business hours (Mon–Fri, 08:00–18:00 GMT+8) |
Your Next Step
Email sales@hangboalloy.com with your 2205 Duplex inquiry:
- Product form: Bar / Tube / Pipe / Plate / Forging
- Dimensions and quantity: OD/WT/ID/thickness × length × pieces
- UNS designation: S32205 (preferred) or S31803 (if required)
- Required standard: ASTM A240 / A276 / A790 / A789 / A182 or NORSOK M-650
- Delivery destination: Street address + preferred incoterm (FOB/CIF/DAP)
- Third-party inspection: SGS / BV / TÜV / DNV / ABS / Lloyd's (specify if required)
Our commercial team responds with a firm quotation and mill-certificate samples within 2 business hours.
