Table of Contents
- Duplex Steel S31803 Overview
- Technical Specifications
- Chemical Composition & Mechanical Properties
- Types of UNS S31803 Hex Bars
- Key Advantages of Duplex Steel S31803 Hex Bars
- Key Applications of Duplex Steel S31803 Hex Bars
- Quality Assurance & Inspection
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
Duplex Steel S31803 Overview
Aurum Overseas is a premier Duplex Steel S31803 Hex Bars Supplier offering high-strength 22% chromium dual-phase hexagon bars for aggressive marine and chemical environments. Our UNS S31803 Hex Bars combine equal ferrite and austenite phases with 3.0–3.5% molybdenum and nitrogen alloying to provide superior resistance to chloride stress corrosion cracking.
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As a trusted Duplex Steel S31803 Hex Bars Exporter, we supply high-precision UNS S31803 Bright Hex Bars for CNC-machined valve trim and heavy UNS S31803 Forged Hex Bars for load-bearing pressure vessel fittings. Every order features solution-annealed stock, EN 10204 3.1 mill test certificates, and custom cut-to-length sawing services.
We deliver certified Duplex Steel F51 Hex Bars directly to offshore oil platforms, desalination units, chemical processing plants, and marine engineering facilities across the USA, Germany, UK, UAE, Saudi Arabia, and global markets.
Technical Specifications
| Technical Parameter | Specification Standard |
|---|---|
| Material Specifications | ASTM A276, ASTM A479, ASME SA276, ASME SA479, EN 10088-3 |
| UNS Designation | UNS S31803 (Dual Certified with UNS S32205 / F51) |
| EN Designation | X2CrNiMoN22-5-3 |
| Across-Flats (AF) Size Range | 6.0 mm to 100.0 mm (1/4" to 4" Hexagon) |
| Length Options | 1,000 mm to 6,000 mm, Precision Sawing Cut-to-Length |
| Surface Finishes | Cold Drawn, Centerless Ground, Bright Annealed, Hot Forged, Rough Machined |
| Heat Treatment Condition | Solution Annealed (1020 °C to 1100 °C, Rapid Water Quench) |
| Dimensional Tolerances | ASTM A484 / ISO 286-2 (h9, h10, h11 hex profile tolerances) |
Chemical Composition & Mechanical Properties
Equivalent Standards
| Standard / Grade | Werkstoff Nr. | UNS Designation | EN Symbol | Common Name |
|---|---|---|---|---|
| Duplex Steel S31803 | 1.4462 | S31803 | X2CrNiMoN22-5-3 | Duplex 2200 / F51 |
Chemical Composition (%)
| Element | Specification Range (UNS S31803) |
|---|---|
| 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 |
| Chromium (Cr) | 22.0 – 23.0 |
| Molybdenum (Mo) | 3.0 – 3.5 |
| Nickel (Ni) | 4.50 – 6.50 |
| Nitrogen (N) | 0.14 – 0.20 |
| Iron (Fe) | 63.72 min |
Mechanical & Physical Properties
| Property Parameter | Value (Metric / Imperial) |
|---|---|
| Density | 7.805 g/cm³ (0.285 lb/in³) |
| Melting Point | 1420 – 1465 °C (2588 – 2669 °F) |
| 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 UNS S31803 Hex Bars
Aurum Overseas supplies Duplex Steel S31803 (F51) hex bars in precision bright and heavy forged conditions for aggressive marine and chemical environments.
UNS S31803 Bright Hex Bars
UNS S31803 Forged Hex Bars
Key Advantages of Duplex Steel S31803 Hex Bars
High Yield Strength
Delivers nearly double the yield strength of standard austenitic stainless steels, allowing reduced cross-sectional wall thickness and lower structural component weight.
Chloride Stress Corrosion Immunity
The balanced 50/50 ferrite-austenite microstructure effectively blocks transgranular stress corrosion cracking in high-salinity marine environments.
Pitting Resistance (PREN ≥ 34)
Chromium (22%), molybdenum (3.0–3.5%), and nitrogen alloying ensure high resistance to localized pitting and crevice corrosion in stagnant aqueous media.
Precision Machining Profile
Accurate across-flats dimensions permit clean thread cutting and efficient machining into high-pressure hex nuts, couplings, and valve stems.
Key Applications of Duplex Steel S31803 Hex Bars
| Industry | Applications | Operational Benefit |
|---|---|---|
| Offshore Oil & Gas | Wellhead tree fasteners, manifold hex bolts, subsea valve stems | Duplex Steel F51 Hex Bars: High strength and resistance to sour gas/chloride corrosion under pressure. |
| Desalination Plants | High-pressure RO pump shafts, brine header hex plugs, flange tie rods | UNS S31803 Hex Bars: Resists localized crevice corrosion and pitting in concentrated saltwater. |
| Chemical Processing | Acid system valves, agitator drive couplings, hex fittings | UNS S31803 Bright Hex Bars: High erosion-corrosion resistance in flowing acidic media. |
| Marine Engineering | Propeller shaft couplings, rudders, structural hardware | UNS S31803 Forged Hex Bars: High fatigue strength and durability in marine splash zones. |
Quality Assurance & Inspection
As an established Duplex Steel S31803 Hex Bars Exporter, every batch undergoes stringent testing protocols to comply with ASTM engineering standards:
- Spectro Chemical Analysis: Positive Material Identification (PMI) ensuring exact 22Cr-5Ni-3Mo-N balance.
- Microstructure & Phase Balance: Metallographic evaluation per ASTM E562 confirming a 40–60% ferrite ratio free of intermetallic sigma phase precipitation.
- Pitting Resistance Verification: Ferric chloride corrosion testing according to ASTM G48 Method A.
Global Export Markets
As an established Duplex Steel S31803 Hex Bars Exporter, Aurum Overseas supplies fully certified UNS S31803 / F51 Hex Bars to global offshore, desalination, 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 S32205 is a dual-certified, higher-cap variation of UNS S31803 that restricts chromium, molybdenum, and nitrogen to the upper end of the range, ensuring guaranteed higher pitting corrosion resistance (PREN ≥ 34).
Hex bars feature flat parallel faces that eliminate extra milling operations when producing high-torque valve stems, hex bolts, threaded plugs, and manifold couplings.
Duplex S31803 hex bars are manufactured in accordance with ASTM A276 and ASTM A479 standards for pressure vessel and general engineering use.
Yes, UNS S31803 offers good weldability using matching 2209 filler metals, provided heat input is controlled to maintain proper ferrite-austenite phase balance in the heat-affected zone.
Contact Aurum Overseas
Partner with a trusted Duplex Steel S31803 Hex Bars Supplier and Duplex Steel S31803 Hex Bars Exporter for certified stock, custom sawing, and reliable global delivery.