Duplex Steel Round Bars — India's Certified Source
Jade Alloys manufactures, stocks, and exports Duplex Steel Round Bars in grades UNS S31803, S32205, S32101, S32304, and S32506 in diameters from 3 mm to 800 mm, supplying industrial projects across six continents. Our duplex round bars combine a dual-phase ferritic-austenitic microstructure that delivers twice the yield strength of standard 316L stainless steel alongside outstanding resistance to chloride pitting, crevice corrosion, and stress corrosion cracking (SCC).
Every bar is manufactured to ASTM A276 / ASME SA276 specifications, tested in our NABL-accredited laboratory, and shipped with an EN 10204 3.1 Mill Test Report for full heat-number traceability. Whether you need a single bar cut to size or a full container for an overseas project, contact Jade Alloys for a same-day quote.
| Trust Factor | Detail |
|---|---|
| NABL-Accredited Lab Testing | Mechanical and chemical properties verified by NABL-approved third-party laboratories; full test certificates included |
| EN 10204 3.1 Mill Test Reports | Heat-traceable MTRs confirming chemical composition, tensile, hardness, and dimensional results with every order |
| NACE MR0175 / ISO 15156 | Sour service certification for oil and gas applications with H₂S exposure, available on request |
| 3 mm – 800 mm Diameter Range | One of India’s widest stocked ranges; custom forged sizes up to 1,000 mm on request |
| 50+ Export Destinations | Weekly shipments to UAE, Saudi Arabia, USA, UK, Germany, Singapore, Australia, and 45+ additional countries |
| Ready Stock & Custom Cutting | Immediate dispatch on standard sizes; cut-to-length service at no extra charge on stocked items |
What Is a Duplex Steel Round Bar?
Our duplex steel bar products are available in the following technical ranges:
A Duplex Steel Round Bar is a precision-formed metal product manufactured from duplex stainless steel an alloy engineered with a two-phase internal microstructure containing roughly equal proportions of austenite and ferrite grains. This dual-phase structure gives duplex steel properties neither phase achieves alone: the high strength and chloride resistance of ferrite, combined with the toughness and weldability of austenite.
Examined metallurgically, a grade S31803 or S32205 bar reveals islands of austenite in a continuous ferritic matrix typically 45–55% ferrite to 45–55% austenite. This balance is engineered by controlling chromium (21–23%), molybdenum (2.5–3.5%), and nitrogen (0.14–0.20%), then locked in through solution annealing at 1025–1100°C followed by rapid water quenching. Nitrogen is particularly critical: it stabilises austenite, prevents harmful sigma phase above 300°C, and directly raises the material’s Pitting Resistance Equivalent Number (PREN).
PREN = %Cr + 3.3 × %Mo + 16 × %N
For grade S32205, this yields a PREN of approximately 35–38, versus ~25 for 316L stainless steel — explaining why duplex is specified for seawater, brine, and chloride-bearing process streams where 316L would fail.
Duplex 2205 vs. Standard Stainless Steel
| Property | Duplex 2205 (S32205) | 316L Stainless | 304 Stainless |
|---|---|---|---|
| Yield Strength (0.2%) | 550 MPa (80 ksi) | 170 MPa (25 ksi) | 205 MPa (30 ksi) |
| Tensile Strength | 800 MPa (116 ksi) | 485 MPa (70 ksi) | 515 MPa (75 ksi) |
| PREN (Pitting Resistance) | ~35–38 | ~25 | ~18 |
| SCC Resistance | Excellent | Susceptible | Susceptible |
| Chloride Pitting | Excellent | Moderate | Low |
| Max Service Temp. | 300°C (572°F) | 870°C (1600°F) | 925°C (1700°F) |
| Weldability | Good (controlled HI) | Excellent | Excellent |
Duplex Steel Round Bar Grades
Jade Alloys stocks and manufactures the complete duplex range — from lean duplex to high-alloy specialist grades. Each grade card below shows its PREN visually so you can immediately compare corrosion resistance across the range.
PREN: 35–38
UNS: S31803 / S32205
EN/WNR: 1.4462
Yield: 550 MPa
UTS: 800 MPa
Global standard for oil & gas, marine, chemical processing and desalination. NACE MR0175/ISO 15156 certified.
PREN: 33–36
UNS: S31803
EN/WNR: 1.4462
Yield: 450 MPa
Std: ASTM A276
Original 2205 designation. Accepted under legacy project standards.
PREN: ~26
UNS: S32101
EN/WNR: 1.4162
Yield: 450 MPa
Ni Substitute: Mn + N
Cost-effective duplex grade for water treatment, coastal structures and pulp & paper.
PREN: ~26
UNS: S32304
EN/WNR: 1.4362
Yield: 400 MPa
Mo-Free: Yes
Economical duplex grade for food, beverage, pharmaceutical and storage tank applications.
PREN: >40
UNS: S32506
EN/WNR: 1.4507
Yield: 550 MPa
W-Added: Yes
Tungsten-enhanced high-performance duplex for offshore, FGD and chlorine-containing services.
PREN: >42
UNS: S32750 / S32760
Grade: 2507 / Zeron 100
Yield: 550 MPa
Stock: Mumbai Ready
For the most aggressive seawater, deep-sea and chemical environments.
Specifications & Technical Data of Duplex Steel Round Bars
Dimensions, Forms & Tolerances
| Parameter | Details |
|---|---|
| Standards | ASTM A276 / ASME SA276, ASTM A479 / ASME SA479, ASTM A182 (forged grades) |
| Round Bar Diameter | 3 mm – 800 mm (custom forged up to 1,000 mm on request) |
| Square Bar | 4 × 4 mm to 100 × 100 mm |
| Flat Bar Thickness | 2 mm – 100 mm |
| Hex Bar | 2 mm – 100 mm across flats |
| Standard Lengths | 3 m (10 ft) to 6 m (20 ft) |
| Custom Lengths | Up to 12 m; forged bars up to 50 ft on request |
| Dimensional Tolerance | H8–H11 (cold-drawn); G5–G6 (precision ground); ISO h9/h10/h11 |
| Surface Finish | Black (hot-rolled), Bright (cold-drawn), Pickled & Passivated, Centreless Ground, Mirror Polished |
| Density | 7.80 – 7.88 g/cm³ |
| Max Hardness | 270 HB (Brinell) |
Chemical Composition — S31803 & S32205
| Element | S31803 (wt%) | S32205 (wt%) |
|---|---|---|
| C | 0.030 max | 0.030 max |
| Mn | 2.00 max | 2.00 max |
| Cr | 21.0 – 23.0 | 22.0 – 23.0 |
| Ni | 4.50 – 6.50 | 4.50 – 6.50 |
| Mo | 2.50 – 3.50 | 3.0 – 3.5 |
| N | 0.08 – 0.20 | 0.14 – 0.20 ✦ |
| Fe | 63.54 min | 63.72 min |
✦ Tighter N minimum in S32205 guarantees higher PREN and minimum yield in every heat.
Mechanical & Physical Properties of Duplex Round Bars
| Property | Value | Unit |
|---|---|---|
| Yield Strength (0.2%) | 550 min | MPa |
| Tensile Strength | 800 min | MPa |
| Elongation | 15 min | % |
| Hardness | 270 max | HB |
| Density | 7,800 | kg/m³ |
| Thermal Conductivity | 15 | W/m·°C |
| Thermal Expansion | 13.7 | μm/m·°C |
| Modulus of Elasticity | 200 | GPa |
| Melting Point | 1,350 | °C |
ISO Dimensional Tolerances of Duplex Steel Round Bars
| Diameter Range (mm) | Permitted Variation (mm) |
|---|---|
| ≥ 6 ≤ 18 | +0 to –0.070 |
| > 18 ≤ 30 | +0 to –0.085 |
| > 30 ≤ 50 | +0 to –0.100 |
| > 50 ≤ 80 | +0 to –0.120 |
| > 80 ≤ 120 | +0 to –0.140 |
| > 120 ≤ 180 | +0 to –0.160 |
| > 180 ≤ 250 | +0 to –0.185 |
| > 250 ≤ 315 | +0 to –0.210 |
| > 315 ≤ 400 | +0 to –0.230 |
| > 400 | +0 to –0.250 |
Duplex Round Bar Weight Chart
Weight formula: Weight (kg/m) = D² ÷ 162 where D = diameter in mm. Use our online metal weight calculator for non-standard sizes.
| Diameter | kg/m | kg/ft | Diameter | kg/m | kg/ft |
|---|---|---|---|---|---|
| 3 mm | 0.055 | 0.017 | 25 mm | 3.871 | 1.180 |
| 4 mm | 0.098 | 0.030 | 1″ (25.4 mm) | 3.970 | 1.210 |
| 5 mm | 0.154 | 0.047 | 30 mm | 5.548 | 1.691 |
| 6 mm | 0.223 | 0.068 | 40 mm | 9.872 | 3.009 |
| 8 mm | 0.398 | 0.120 | 1½” (38.1 mm) | 8.951 | 2.715 |
| 10 mm | 0.620 | 0.189 | 50 mm | 15.38 | 4.690 |
| 12 mm | 0.889 | 0.271 | 2″ (50.8 mm) | 15.900 | 4.847 |
| 16 mm | 1.578 | 0.481 | 3″ (76.2 mm) | 35.762 | 10.900 |
| 20 mm | 2.470 | 0.753 | 4″ (101.6 mm) | 63.340 | 19.306 |
Manufacturing Process
Every Jade Alloys duplex round bar passes through six controlled production stages, each governed by the precise parameters that determine final phase balance, corrosion resistance, and mechanical integrity.
EAF Melting & AOD Refining
Raw materials are charged into an Electric Arc Furnace (EAF) and melted above 1,550°C, then transferred to an Argon Oxygen Decarburisation (AOD) converter. The AOD reduces carbon below 0.030% without sacrificing chromium yield and enables precise nitrogen addition critical for S32205 pitting resistance.
Continuous Casting & Billet Formation
The refined melt is poured into a continuous casting machine to produce billets with uniform chemistry throughout the cross-section. Continuous casting minimises macro-segregation and ensures consistent properties. All billets are visually and ultrasonically inspected before hot working.
Hot Rolling & Forging
Billets are worked through calibrated rolling mill passes or forging presses at 1,100–1,250°C. This refines grain structure, closes internal voids, and shapes the profile. Bars above 150 mm diameter are open-die forged for full through-section integrity.
Solution Annealing – Phase Balance Restoration
Bars are heated to 1,025–1,100°C and rapidly water-quenched. This critical step dissolves sigma phase, chi phase, and carbide precipitates while restoring the correct 50/50 ferrite-austenite balance required for duplex performance.
Descaling & Surface Treatment
Mill scale is removed by mechanical shot-blasting followed by controlled pickling in HNO₃/HF acid. Additional centreless grinding and polishing operations can achieve surface roughness values as low as Ra 0.4 μm.
Dimensional Inspection, Testing & Marking
Every bar is dimensionally inspected to ISO tolerances. Tensile, hardness, UT/ET, and chemical analysis are performed for full compliance. Each bar is marked with heat number, grade, size, and ASTM specification for complete traceability.
Certifications & Testing
Every Duplex Steel Round Bar order ships with a complete documentation package that procurement and QA teams worldwide rely on.
📄 Mill Test Report
Chemical composition and mechanical properties traceable to the specific heat number.
🧪 NABL Lab Testing
Independent verification of tensile strength, yield strength, hardness, and chemical composition.
🛢️ Sour Service
Suitability for H₂S-containing oil & gas environments with verified hardness compliance.
🔬 Intermetallic Phase Test
Confirms absence of detrimental sigma and chi phases after welding or heat treatment.
🛡️ IGC Test
Verifies immunity to sensitisation-induced intergranular corrosion.
⚡ PMI Verification
On-site elemental verification to confirm material grade identity before installation.
📡 NDT Testing
Subsurface defect detection for critical and large-diameter bars.
🌍 Export Documentation
Complete export paperwork for customs clearance and import duty preferences worldwide.
For EN 10204 3.2 (witnessed by an approved TPI body such as SGS or Bureau Veritas), please specify at enquiry and allow additional lead time.
Applications by Industry
🛢️ Oil & Gas
Duplex 2205 round bars are specified for wellhead components, valve stems, pump shafts, manifold connectors, and instrumentation fittings in H₂S, CO₂, and chloride-rich environments. NACE MR0175 compliant with 550 MPa yield strength.
🌊 Marine & Offshore
Used for propeller shafts, rudder pintles, deck hardware, mooring systems, platform structures, and heat exchanger tube sheets exposed to seawater and chloride-rich conditions.
⚗️ Chemical & Petrochemical
Ideal for agitator shafts, reactor internals, heat exchanger baffles, centrifuge components, and structural supports handling acids, chlorides, and caustic chemicals.
💧 Desalination & Water Treatment
Widely used for pump shafts, impellers, brine heater tube sheets, pipeline flanges, and evaporator structures in RO and MSF desalination plants.
⚡ Power Generation
Applied in cooling water systems, valve bodies, pump shafts, heat exchanger supports, and FGD units requiring high resistance to chlorides and wet SO₂ environments.
🏭 Pulp, Paper & Food Processing
Used in washer drum shafts, press rolls, screen supports, agitators, pumps, and hygienic processing equipment exposed to aggressive bleaching chemicals.
Price Guide & Export Delivery
Duplex steel round bar pricing is influenced by LME rates for chromium, nickel, and molybdenum, along with order quantity, bar diameter, surface finish, and certification level. Contact Jade Alloys for a firm quotation valid for 30 days, inclusive of MTR and NABL test certificates.
| Diameter Range | Typical CIF Price (USD/kg) | Surface Finish | Lead Time (Ex-Stock) |
|---|---|---|---|
| 3 mm – 20 mm | USD 7.00 – 8.50 | Bright / Cold-Drawn | 1–5 working days |
| 20 mm – 50 mm | USD 6.24 – 7.50 | Black / Bright | 1–7 working days |
| 50 mm – 100 mm | USD 6.00 – 7.00 | Black / Peeled | 3–10 working days |
| 100 mm – 300 mm | USD 6.74+ | Black / Rough-Turned | 7–21 working days |
| 300 mm – 800 mm (Forged) | Price on request | Rough-Turned / Machined | 4–8 weeks |
All prices are indicative and subject to change with LME alloy market movements. Contact Jade Alloys for a firm quotation. HS Code for duplex stainless steel round bars: 72221119.
Export Destinations
All exports supplied with commercial invoice (HS Code 72221119), packing list, certificate of origin, and fumigation certificate. Incoterms: FOB, CIF, DAP, DDP on request.
Explore the Full Range
Duplex Steel Round Bars — Same-Day Quotation
Ready stock in Mumbai • EN 10204 3.1 MTC • NACE MR0175 • ISO 9001:2015 • Same-week dispatch to 50+ countries
