Table of Contents
- Duplex Steel S31803 (F51) Washers Overview
- Technical Specifications
- Technical Properties & Chemical Composition
- Types of Duplex Steel S31803 (F51) Washers
- Key Technical Advantages
- Target Industry Applications
- Quality Assurance & Inspection Standards
- Global Export Markets
- Frequently Asked Questions
- Contact Aurum Overseas
Duplex Steel S31803 (F51) Washers Suppliers & Exporters
If your subsea pipelines, offshore platforms, or chemical processing equipment demand high tensile strength alongside immunity to chloride stress corrosion cracking, you've reached the right source. As a leading Duplex Steel S31803 Washers Supplier and Duplex Steel S31803 Washers Exporter, Aurum Overseas manufactures precision Plain, Spring, Lock, Square, and Conical fasteners to ASME B18.21.1, DIN 125, and ISO 7089 standards.
Our UNS S31803 Washers feature a balanced 50/50 austenitic-ferritic microstructure that doubles the yield strength of standard 316 stainless steel fasteners. Complete with full EN 10204 3.1 MTR certifications, we maintain extensive stock of Duplex F51 Washers ready for rapid global dispatch.
Technical Specifications
| Parameter | Technical Specification / Standard Range |
|---|---|
| Material Grade | Duplex Steel S31803 |
| Forging Designation | ASTM A182 Grade F51 |
| UNS Designation | UNS S31803 |
| Manufacturing Standards | ASTM A240, ASME SA240, ASTM A182, ASME SA182 |
| Dimensional Specifications | ASME B18.21.1, DIN 125 A/B, DIN 127, DIN 9021, ISO 7089, ISO 7090 |
| Washer Types | Plain Washers, Spring Washers, Lock Washers, Square Washers, Conical Washers |
| Size Capability | Imperial: #4 to 4" NB | Metric: M3 to M100 |
| Thickness Range | 0.5 mm to 12 mm |
| Heat Treatment Condition | Solution Annealed (1020°C – 1100°C) + Rapid Water Quenched |
| Hardness Limit | ≤ 31 HRC / ≤ 290 HB |
| PREN Rating | ≥ 34 (Pitting Resistance Equivalent Number) |
| Certification | EN 10204 3.1 MTR, PMI Verification, Ferrite Content Test (ASTM E562) |
Technical Properties & Chemical Composition
Equivalent Grades of Duplex Steel S31803 Washers
| STANDARD | WERKSTOFF NR. | UNS |
|---|---|---|
| Duplex S31803 / F51 | 1.4462 | S31803 |
Chemical Composition of UNS S31803 (F51) Washers (%)
| Element | Duplex S31803 (F51) (%) |
|---|---|
| Chromium (Cr) | 21.00 – 23.00 |
| Nickel (Ni) | 4.50 – 6.50 |
| Molybdenum (Mo) | 2.50 – 3.50 |
| Nitrogen (N) | 0.08 – 0.20 |
| Carbon (C) | ≤ 0.030 |
| Manganese (Mn) | ≤ 2.00 |
| Silicon (Si) | ≤ 1.00 |
| Phosphorus (P) | ≤ 0.030 |
| Sulfur (S) | ≤ 0.020 |
| Iron (Fe) | Balance |
Mechanical Properties of UNS S31803 Washers
| Property | Metric Value | Imperial Value |
|---|---|---|
| Ultimate Tensile Strength | ≥ 620 MPa | ≥ 90,000 psi |
| Yield Strength (0.2% Proof Stress) | ≥ 450 MPa | ≥ 65,000 psi |
| Elongation (%) | ≥ 25% | ≥ 25% |
| Hardness (Rockwell C / Brinell) | ≤ 31 HRC | ≤ 290 HB |
| Density | 7.805 g/cm³ | 0.285 lb/in³ |
| Melting Point Range | 1420°C – 1465°C | 2588°F – 2669°F |
Types of Duplex Steel S31803 (F51) Washers
Aurum Overseas supplies a comprehensive range of duplex steel washer configurations manufactured according to standard DIN, ASME, and ISO dimensional tolerances for multiple engineering assemblies.
Duplex Steel S31803 Plain Washers
Duplex Steel S31803 Spring Washers
Duplex Steel S31803 Lock Washers
Duplex Steel S31803 Square Washers
Duplex Steel S31803 Conical Washers
Key Technical Advantages
High Yield Strength Load Bearing
Yield strength exceeding 450 MPa allows engineers to utilize thinner washer profiles while retaining maximum clamp load.
Resistance to Stress Corrosion Cracking
The dual-phase microstructure prevents SCC propagation in warm chloride and marine splash environments.
Nitrogen-Enhanced Pitting Defense
Controlled nitrogen addition elevates localized pitting and crevice corrosion resistance (PREN ≥ 34).
Superior Erosion Resistance
Resists high-velocity fluid flow and particulate erosion in downstream oil and gas piping.
Target Industry Applications
| Industry Sector | Application | Operating Environment |
|---|---|---|
| Offshore Marine & Subsea | Subsea Christmas trees, manifold bolting, and seawater pumps | Deep-water hydrostatic pressures and continuous marine immersion |
| Chemical Processing | Reactor vessel flanges, heat exchangers, and organic acid lines | Corrosive chloride solutions and warm acid processing |
| Oil & Gas Downstream | Hydrotreater flanges, separator vessels, and refinery piping | Sour gas (H₂S) streams requiring NACE MR0175 compliance |
| Pulp & Paper Manufacturing | Bleaching towers, digesters, and liquor circulation pumps | Aggressive chlorine dioxide environments and elevated temperatures |
| Desalination Plants | High-pressure reverse osmosis pumps and brine manifold flanges | High-concentration saline solutions and continuous chloride exposure |
Quality Assurance & Inspection Standards
- Phase Balance Verification: Ferrite testing per ASTM E562 ensures a balanced 40–60% ferrite matrix to avoid embrittlement.
- Spectrometric PMI Testing: Positive Material Identification checks confirm precise Cr, Ni, Mo, and N elemental balance.
- Corrosion Resistance Testing: ASTM G48 Method A testing verifies critical pitting temperature compliance.
- Dimensional Precision Check: Digital gauges ensure strict adherence to ASME B18.21.1 and ISO standard limits.
Global Export Markets
Aurum Overseas supplies fully certified Duplex Steel S31803 Washers to industrial projects across:
USA
Canada
Mexico
Germany
United
Kingdom
France
Italy
Netherlands
Norway
UAE
Saudi
Arabia
Qatar
Kuwait
Oman
Singapore
Malaysia
Australia
Frequently Asked Questions
Duplex S31803 has a dual austenitic-ferritic structure that yields twice the proof stress (≥450 MPa) of standard 316L.
The recommended maximum service limit is 300°C (572°F) to avoid embrittling intermetallic phase precipitation.
Yes. UNS S31803 washers comply with NACE MR0175 / ISO 15156 standards for H₂S sour oilfield service.
Yes. Their high yield strength prevents permanent deformation under heavy initial bolt preload.
Orders include full EN 10204 3.1 Material Test Reports covering chemistry, mechanical tests, heat treatment, and PMI checks.
Contact Aurum Overseas
Aurum Overseas provides rapid delivery of certified Duplex Steel S31803 Washers for global industrial applications.
Contact our sales engineering team for technical assistance, material certifications, and rapid pricing.