Table of Contents
- Duplex Steel S31803 Overview
- Technical Specifications
- Chemical Composition & Mechanical Properties
- Types of Duplex S31803 (F51) Square Bars
- Duplex Steel S31803 vs. S32205
- Key Advantages
- Key Applications
- Quality Testing & Inspection
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
Duplex Steel S31803 Square Bar Overview
Aurum Overseas is a leading Duplex Steel S31803 Square Bars Supplier stocking 22% chromium dual-phase profiles. With a 50/50 ferritic-austenitic structure, our solid square stock offers twice the yield strength of standard austenitic grades plus superior pitting and stress corrosion resistance.
As a certified Duplex Steel S31803 Square Bars Exporter, we supply cold-drawn Duplex S31803 Bright Square Bars for machining and heavy Duplex S31803 Forged Square Bars for structural frames. All stock comes with heat traceability, mill test certification, and custom cut-to-length options.
We supply certified Duplex Steel F51 Square Bars and UNS S31803 Square Bars to offshore, desalination, and chemical sectors across the USA, Canada, Germany, UK, UAE, Saudi Arabia, and global markets.
Technical Specifications
| Technical Parameter | Specification Details |
|---|---|
| Material Specifications | ASTM A276, ASTM A479, ASME SA276, ASME SA479, ASTM A182 (F51) |
| UNS Designation | UNS S31803 |
| Size Range (Square) | 6.0 mm x 6.0 mm to 250 mm x 250 mm (1/4" to 10" square) |
| Length Options | 1,000 mm to 6,000 mm, Custom Cut-to-Length |
| Surface Finishes | Bright (Cold Drawn / Centerless Ground), Forged (Hot Forged / Rough Turned) |
| Heat Treatment | Solution Annealed (1020 °C – 1100 °C followed by rapid water quench) |
| Dimensional Tolerances | ASTM A484 / ISO h9, h10, h11 square profile tolerances |
Chemical Composition & Mechanical Properties
Equivalent Standards
| Standard Grade | UNS | Werkstoff Nr. | EN Standard | AFNOR |
|---|---|---|---|---|
| Duplex 2205 / F51 | S31803 | 1.4462 | X2CrNiMoN22-5-3 | Z3 CND 22-05 Az |
Chemical Composition (%)
| Element | Composition Standard Range (%) |
|---|---|
| Chromium (Cr) | 22.0 – 23.0 |
| Nickel (Ni) | 4.50 – 6.50 |
| Molybdenum (Mo) | 3.0 – 3.5 |
| Nitrogen (N) | 0.14 – 0.20 |
| Carbon (C) | 0.030 max |
| Manganese (Mn) | 2.00 max |
| Silicon (Si) | 1.00 max |
| Phosphorus (P) | 0.030 max |
| Sulfur (S) | 0.020 max |
| Iron (Fe) | 63.72 min (Balance) |
Physical & Mechanical Properties
| Property Parameter | Technical Value |
|---|---|
| Density | 7.805 g/cm³ (0.285 lb/in³) |
| Melting Range | 1420 °C – 1465 °C (2588 °F – 2669 °F) |
| PREN (Pitting Resistance Equivalent No.) | ≥ 34 |
| Tensile Strength (Min) | 620 MPa (90,000 psi) |
| Yield Strength (0.2% Offset, Min) | 450 MPa (65,000 psi) |
| Elongation (Min) | 25% |
| Hardness (Max) | 290 HBW (31 HRC) |
Types of Duplex S31803 (F51) Square Bars
Aurum Overseas supplies Duplex Steel S31803 (F51) square bars in precision bright and heavy forged conditions for high-strength and corrosion-resistant industrial applications.
Duplex S31803 Bright Square Bars
Duplex S31803 Forged Square Bars
Duplex Steel S31803 vs. S32205
| Comparison Feature | Duplex S31803 (F51) | Duplex S32205 (F60) |
|---|---|---|
| Microstructure | Dual-phase (Ferritic-Austenitic) | Dual-phase (Ferritic-Austenitic) |
| Yield Strength (Min) | 450 MPa (High load capacity) | 450 MPa (Tighter element limits) |
| Chromium & Nitrogen | 22% Cr, 0.14–0.20% N | 22.5% Cr, 0.15–0.20% N |
| Pitting Resistance (PREN) | ≥ 34 (Resists marine pitting) | ≥ 35 (Higher localized resistance) |
| Best Buyer Choice For | Cost-effective offshore shafts & marine valves | Stringent oil & gas specifications |
Key Advantages
Double Yield Strength
Delivers over twice the strength of 316L, allowing lighter structural designs and reduced material weight.
Chloride Pitting Protection
PREN ≥ 34 stops localized pitting and crevice corrosion in seawater and brackish environments.
Stress Corrosion Resistance
Balanced dual-phase structure prevents stress corrosion cracking in high-salinity applications.
Lower Material Cost
Reduced nickel content (4.5–6.5%) maintains stable pricing compared to high-nickel austenitic alloys.
Key Applications
| Industry Sector | Component Type | Primary Application Advantage |
|---|---|---|
| Offshore Oil & Gas | Wellhead components, valve stems, pump shafts | Resists sour gas (H2S) environment cracking and high subsea pressure. |
| Desalination Plants | High-pressure pump bodies, seawater manifold bars | Eliminates severe chloride pitting in concentrated brine flows. |
| Chemical Processing | Agitator shafts, heat exchanger frame billets | Handles hot organic and inorganic acids without rapid surface erosion. |
| Marine Engineering | Propeller shafting, rudder stocks, deck tie-downs | Superior fatigue resistance under continuous saltwater wave action. |
Quality Testing & Inspection
As a quality-focused Duplex Steel S31803 Square Bars Supplier, every shipment undergoes strict quality control:
- Mill Test Certification: Full compliance with EN 10204 3.1 detailing heat numbers, chemical composition, and heat-treatment cycles.
- Ferrite Phase Content Testing: Metallographic analysis confirming a balanced 40%–60% ferrite range according to ASTM E562.
- Pitting Corrosion Testing: Ferric chloride pitting test performed per ASTM G48 Method A to ensure localized corrosion resistance.
- Non-Destructive Inspection (NDT): Ultrasonic internal testing per ASTM A388 on forged square stock to verify structural density.
Global Export Markets
As an established Duplex Steel S31803 Square Bars Exporter, Aurum Overseas supplies fully certified UNS S31803 / F51 Square Bars to global energy and marine engineering centers:
USA
Canada
Mexico
Germany
United Kingdom
France
Italy
Netherlands
Belgium
Spain
Poland
UAE
Saudi Arabia
Qatar
Kuwait
Oman
Bahrain
Frequently Asked Questions
UNS S31803 is the original 22% chromium duplex grade. UNS S32205 has tighter minimum chemistry controls, giving slightly higher corrosion resistance. Most of our stock is dual-certified S31803/S32205.
F51 is the ASTM A182 forging designation corresponding to UNS S31803 chemistry and mechanical strength requirements.
We supply cold-drawn Bright Square Bars for smooth machining and hot-forged Forged Square Bars for heavy structural framing.
Yes, as a Duplex Steel S31803 Square Bars Exporter, every delivery includes certified EN 10204 3.1 mill test certificates.
Contact Aurum Overseas
Aurum Overseas supplies certified Duplex Steel S31803 (F51 / 1.4462) square bars for marine, oil and gas, and chemical equipment manufacturing.
Contact our sales team for stock availability, custom cutting, or fast pricing: