Alloy 825 (UNS N08825, W.Nr.2.4858) for marine & offshore industry is the global standard cost-effective nickel superalloy for medium-severity corrosion environments. It fills the critical performance gap between stainless steel and high-cost Hastelloy/Inconel alloys, delivering exceptional resistance to sulfuric acid, chloride-induced SCC and sour gas at 40-50% lower material cost than premium alloys.
As the most widely specified alloy for offshore seawater systems and moderate sour service, Alloy 825 features titanium stabilization that eliminates intergranular corrosion after welding, requiring no post-weld heat treatment. Emily PIPE supplies classification society-certified Alloy 825 seamless pipes, welded pipes, bars and forgings fully compliant with NACE MR0175/ISO 15156 and API standards.
| Item | Details |
|---|---|
| Executive Standards | 1. International Material Standards: ASTM B423 (Seamless Pipe), ASTM B705 (Welded Pipe), ASTM B425 (Bar/Rod), ASTM B564 (Forgings)
2. Offshore Standards: NACE MR0175/ISO 15156-3, API 5LC, API 6A 3. Marine Standards: ABS, DNV, LR, BV, CCS, RINA 4. Pressure Vessel Standards: ASME Section VIII Div.1 5. Testing Standards: ASTM E8, ASTM G48 (Pitting/Crevice), ASTM E243 (Eddy Current) |
| Material Grade | 1. Standard Offshore Grade: Alloy 825 (UNS N08825), solution annealed
2. NACE Certified Grade: Hardness ≤22 HRC for sour service applications 3. Welding Grade: Low carbon content for improved weldability 4. Equivalent Grades: NS1402 (China), Incoloy 825 (USA), Nicrofer 4221 (Germany) |
| Chemical Composition (Weight %) | 1. Nickel (Ni): 38.0-46.0 (base element for SCC resistance)
2. Chromium (Cr): 19.5-23.5 (oxidizing acid resistance) 3. Molybdenum (Mo): 2.5-3.5 (reducing acid and pitting resistance) 4. Copper (Cu): 1.5-3.0 (key element for sulfuric acid resistance) 5. Titanium (Ti): 0.6-1.2 (stabilizes against intergranular corrosion) 6. Iron (Fe): ≥22.0 (improves formability and reduces cost) 7. Carbon (C): ≤0.05, Manganese (Mn): ≤1.00, Sulfur (S): ≤0.030 |
| Mechanical Properties (Annealed State) | 1. Tensile Strength (RT): 585-795 MPa
2. 0.2% Yield Strength (RT): ≥240 MPa 3. Elongation (δ5): ≥30% 4. Hardness (HB): 130-200 5. Tensile Strength (400℃): ≥400 MPa 6. Maximum Continuous Service Temperature: 425℃ |
| Dimensional Tolerance | 1. Seamless Pipes/Tubes: Ø6-50mm ±0.15mm; Ø50-150mm ±0.3mm; Wall thickness ±0.08-0.12mm
2. Welded Pipes: Ø10-600mm ±0.2mm; Wall thickness ±0.10mm 3. Bars/Rods: Ø6-50mm ±0.3mm; Ø50-300mm ±0.6mm; Straightness ≤0.3mm/m 4. U-Bend Tubes: Bend radius ±0.5mm; Ovality at bend ≤3% of OD 5. Length Tolerance: ±2mm (1-12m); custom lengths up to 18m available |
| Why This Material Is Used in Marine & Offshore Industry | 1. Unmatched Cost-Effectiveness:
– 40-50% lower material cost than Hastelloy C276 and Inconel 625 – 5-10 times longer service life than 316L stainless steel in aggressive environments – Reduces total cost of ownership by 60-70% compared to stainless steel 2. Superior Chloride SCC Resistance: – 38-46% nickel content provides excellent immunity to chloride-induced stress corrosion cracking – Resists cracking in seawater and brine solutions up to 30,000 ppm Cl⁻ – Eliminates the most common failure mode in marine piping systems 3. Excellent Acid Resistance: – Specifically formulated for 20-40% boiling sulfuric acid, the most corrosive range for stainless steels – Good resistance to phosphoric acid, nitric acid and organic acids – Ideal for acid gas removal systems and produced water handling 4. Proven Sour Service Performance: – NACE MR0175 certified for H₂S partial pressures up to 200 psi at 175℃ – Resists sulfide stress cracking (SSC) in moderate sour environments – Suitable for offshore oil and gas production with medium sulfur content 5. Superior Field Fabricability: – Titanium stabilization eliminates carbide precipitation in weld heat-affected zones – No post-weld heat treatment required, critical for remote offshore installations – Excellent weldability with all conventional welding processes |
| Application Scenarios and Corresponding Customers | 1. FPSOs and FLNGs:
– Applications: Seawater cooling systems, produced water handling, acid gas removal units, heat exchangers, process piping – Customers: ExxonMobil, Shell, BP, Chevron, TotalEnergies, CNOOC 2. Offshore Oil and Gas Production: – Applications: Wellhead components, Christmas trees, flowlines, manifolds, umbilicals, valve bodies – Customers: TechnipFMC, Schlumberger, Halliburton, Baker Hughes, Aker Solutions 3. Offshore Wind Farms: – Applications: Foundation fasteners, turbine internals, transformer cooling systems, subsea cables, corrosion-resistant cladding – Customers: Ørsted, Vestas, Siemens Gamesa, Goldwind, Envision Energy 4. Chemical and Product Tankers: – Applications: Cargo tank piping, heat exchangers, pump and valve components, vent systems – Customers: Stolt-Nielsen, Odfjell, Navig8, Maersk Tankers, Sinochem Shipping 5. Seawater Desalination Plants: – Applications: Brine processing lines, heat exchanger tubes, high-pressure pumps, reverse osmosis systems – Customers: DuPont Water Solutions, Veolia, SUEZ, Acciona Agua |
| Customer Requirements in This Industry | 1. Performance Requirements:
– Chloride SCC Resistance: Must be immune to stress corrosion cracking in seawater – Sour Service Resistance: Must meet NACE MR0175 requirements for H₂S – Acid Resistance: Must withstand sulfuric acid and produced water environments – Fatigue Resistance: Must withstand cyclic loads from wave action and vibration – Weldability: Must be easily weldable without post-weld heat treatment 2. Quality and Compliance Requirements: – NACE and API Certification: Must provide NACE MR0175 and API 5LC certification – Classification Society Approval: Must be approved by ABS, DNV, LR or equivalent – Full Traceability: Must provide complete traceability from raw material to finished product – Third-Party Inspection: Must allow inspection by independent offshore inspectors – Material Certification: Must provide EN 10204 3.2 mill test reports 3. Manufacturing Requirements: – Precision Dimensional Tolerances: Must meet tight tolerances for proper fit and assembly – Surface Quality: Must have smooth surfaces to reduce flow resistance and corrosion initiation – Internal Quality: Must be free from inclusions, porosity and segregation (100% UT/ET verified) – Consistent Quality: Must have uniform chemical composition across all batches – Customization: Must produce custom sizes and shapes per customer drawings |
| Common Related Products in This Industry | 1. Alloy 825 Seamless Pipes/Tubes: For seawater cooling, hydraulic lines and heat exchangers
2. Alloy 825 Welded Pipes: Cost-effective for large-diameter process and seawater piping 3. Alloy 825 U-Bend Tubes: Custom bent tubes for offshore heat exchangers and condensers 4. Alloy 825 Bars/Rods: For valve stems, pump shafts, fasteners and machined components 5. Alloy 825 Forgings: Custom forgings including flanges, valve bodies, pump casings and manifolds 6. Alloy 825 Fasteners: Bolts, nuts, screws, studs and washers for offshore applications 7. Alloy 825 Welding Materials: ERNiFeCr-1 electrodes and wires for offshore welding 8. Alloy 825 Sheets and Plates: For tank liners, splash zone cladding and structural components 9. Alloy 825 Machined Components: Precision-machined valves, fittings and pump parts 10. Custom Fabricated Assemblies: Pre-fabricated piping spools and heat exchanger bundles |
| Why Choose Us (Emily PIPE) | 1. 20+ Years of Offshore Alloy Expertise: We have supplied Alloy 825 products to over 250 offshore projects worldwide
2. Full NACE, API and Classification Society Certification: Our production line meets the strictest offshore industry standards 3. Full-Process Quality Control: We implement 100% ultrasonic, eddy current and hydrostatic testing on all products 4. Complete International Certifications: Our products hold ASTM, ASME, PED, NACE and marine certifications 5. Advanced Customization Capability: We can produce custom sizes, lengths and shapes per your drawings 6. Strategic Inventory Management: We maintain 300+ tons of Alloy 825 inventory to support urgent offshore requirements 7. Global Logistics Network: We have experience delivering to remote offshore locations worldwide 8. One-Stop Solution: We provide complete solutions from raw material supply to pre-fabricated assemblies |
| Supplementary Industry Information | 1. Comprehensive Test Reports: Each batch comes with a full MTR including chemical analysis, mechanical properties and NDT results. SSC and HIC test reports available upon request
2. Full Material Traceability: Every product has a unique heat number and complete traceability documentation from ingot to finished product 3. Value-Added Processing: We offer precision cutting, CNC bending, welding, end processing and surface finishing services 4. Emergency Response Service: We provide 24/7 emergency support for offshore shutdown requirements 5. Market Growth: The global Alloy 825 market for marine & offshore industry is projected to grow at a CAGR of over 6% through 2030, driven by offshore wind farm construction and deep-water oil & gas development 6. Sustainability Commitment: All our products are manufactured using sustainable practices and are 100% recyclable |
| Packaging | 1. Plastic Caps: All pipe/bar ends are protected with heavy-duty polyethylene caps with internal sealing rings to prevent contamination
2. Waterproof Film: Each product is individually wrapped in waterproof and anti-corrosion film 3. Bundle Packing: Products of the same size are bundled with steel straps and wooden spacers to prevent contact damage 4. Wooden Case: Bundles are packed in sturdy fumigated wooden cases with steel reinforcement for international shipping 5. Export Standard Packing: All packaging complies with international export standards and ISPM 15 regulations 6. Marking: Each package is clearly marked with product specifications, heat number, batch number, quantity and destination |
Looking for Alloy 825 pipe, bar or forging for marine & offshore applications? Send us your dimensions, application requirements and certification standards. We will provide a customized quotation and technical data sheet within 12 hours.