Monel 400 Round Bar
Monel 400 Round Bar is a nickel-copper alloy engineered to dominate reducing and acidic conditions where conventional steels fail. With a unique 67% Ni-30% Cu matrix, it thrives in seawater, hydrofluoric acid, and alkaline media, delivering unmatched durability for subsea systems, chemical reactors, and sour gas infrastructure. Its dual-phase structure resists pitting, stress corrosion cracking, and erosion at temperatures up to 540°C.
Global Compliance & Traceability
| Region | Standard | Grade Designation |
|---|---|---|
| USA | ASTM B164 | UNS N04400 |
| Europe | EN 2.4360 | NiCu30Fe |
| Japan | JIS NW4400 | - |
| Offshore | NORSOK MDS D40 | Class 4 (Subsea Compliance) |
| Global | ISO 6208 | NiCu30Al |
Material Science Precision
Alloy Architecture
Nickel (Ni): 63–70% – Forms the corrosion-resistant backbone.
Copper (Cu): 28–34% – Enhances reducing acid resistance.
Iron (Fe): ≤2.5% – Balances thermal conductivity.
Manganese (Mn): ≤2.0% – Suppresses sulfur embrittlement.
Surface Engineering
Hot-Rolled Finish: Scale-free surface (Ra ≤3.2μm).
Cold-Drawn Precision: Mirror polish (Ra ≤0.4μm) for hygienic applications.
Performance Dominance
| Property | Metric | Industry Benchmark |
|---|---|---|
| Seawater Corrosion | 0.0025 mm/yr (ASTM G46) | 10x better than 316L stainless steel |
| Hydrofluoric Acid | ≤0.05 mm/yr (40% HF @ 80°C) | The only HF-resistant alloy that can be processed and formed. |
| Tensile Strength | 550–780 MPa (Annealed) | After cold drawing, it can reach 1,100 MPa. |
| Thermal Conductivity | 21 W/m·K (20–100°C) | Superior to Hastelloy C276 |
5 Unparalleled Advantages
Subsea Survivor
Zero crevice corrosion after 10+ years in 3.5% NaCl (per NACE TM0177).
Acid Alchemist
Handles concentrated sulfuric (≤70%) and hydrochloric acids (≤1.5%) without intergranular attack.
Cryogenic Champion
Maintains 40 J impact toughness at -196°C (LNG valve stems).
Biofouling Resistance
80% lower marine organism adhesion vs. titanium (ISO 22196).
Recyclability Edge
95% end-of-life recovery rate; RINA sustainability certified.
Cross-Sector Applications
| Industry | Mission-Critical Uses |
|---|---|
| Offshore Oil & Gas | Downhole tubing, Christmas tree components |
| Chemical Processing | HF alkylation units, acetic acid reactors |
| Marine Engineering | Propeller shafts, desalination brine heaters |
| Power Generation | Feedwater heaters, geothermal steam separators |
| Pharmaceutical | Reaction vessels under HCl/Cl₂ environments |
Technical Intelligence Hub
Q1: Welding best practices for sour service?
A: Use ERNiCu-7 filler with argon shielding; post-weld solution anneal at 870°C for H₂S resistance (NACE MR0175 compliant).
Q2: How to prevent stress corrosion cracking in chlorides?
A: Maintain hardness ≤22 HRC via annealing; avoid cold work >15% in stagnant seawater.
Q3: Comparison to Duplex 2205?
A: Monel 400 excels in reducing acids; Duplex outperforms in oxidizing media like nitric acid.
Q4: Surface treatment for high-velocity seawater?
A: Electroless Ni-P coating (50μm) reduces erosion by 60% (ASTM G73).
Q5: Lead time for large diameters?
A: 20–30 days for 300mm+ Ø; vacuum-arc remelted (VAR) stock available.
Strategic Procurement Benefits
NACE Certified
Full H₂S/CO₂ compatibility testing per NACE TM0284-2016.
Dimensional Mastery
Diameters: 6mm–500mm | Lengths: 1m–12m (±0.1mm/m straightness).
Global Stockpile
Immediate pickup from Houston, Stavanger, and Singapore hubs.
Value-Add Services
Non-destructive testing (UT/RT), PMI verification, cryogenic conditioning.
Keywords: Monel 400 Round Bar, Nickel-Copper Alloy, Hydrofluoric Acid Resistant, Subsea Metal, NACE-Compliant Bar Stock
