Monel 400 Nickel-Copper Alloy Coil Tube
Wenzhou Jixing Metal Materials Co., Ltd. presents a premium-grade Monel 400 (UNS N04400) coil tube, engineered for the most demanding corrosion-resistant applications in marine, chemical, and energy industries. Composed of a 67% nickel and 30% copper binary alloy, this product delivers exceptional resistance to seawater, hydrofluoric acid (HF), and alkaline environments — making it an indispensable solution where conventional stainless steels fail.
Product Overview
The Monel 400 coil tube is a cold-worked, continuous-coil form of nickel-copper alloy tubing, supplied in large-diameter coils for maximum fabrication efficiency and minimal waste. Its unique metallurgical composition provides outstanding resistance to a wide range of corrosive media, particularly in non-oxidizing reducing acids, marine environments, and high-chloride solutions. The coil format enables seamless bending, forming, and welding into complex heat exchange configurations, pressure vessels, and process piping systems without the need for extensive joint welding.
Unlike austenitic stainless steels that are susceptible to pitting and crevice corrosion in chloride-rich environments, Monel 400 maintains its structural integrity and surface finish even under prolonged exposure to aggressive chemical conditions. This makes it the material of choice for critical process equipment in the petrochemical, marine engineering, and acid processing sectors.
Material & Properties
Monel 400 is a precipitation-strengthenable nickel-copper alloy with superior resistance to nearly all chemical environments. The key performance characteristics include:
- Chemical Resistance: Excellent resistance to seawater, brine, hydrofluoric acid (HF), hot concentrated alkalis, and most organic and inorganic acids (non-oxidizing)
- Mechanical Strength: High tensile strength and ductility retained at both ambient and elevated temperatures up to 450°C
- Thermal Stability: Maintains corrosion resistance and mechanical properties across a broad temperature range of -196°C to +450°C
- Weldability: Excellent weldability with standard inert-gas welding methods; post-weld heat treatment available for stress relief
- Non-magnetic: Suitable for applications requiring magnetic neutrality
- Low thermal conductivity: Provides inherent thermal insulation in heat exchange applications
Specifications
| Parameter | Specification |
|---|---|
| Alloy Designation | Monel 400 / UNS N04400 / Alloy 400 |
| Chemical Composition | Ni ≥ 67%, Cu ≥ 28%, Fe ≤ 2.5%, Mn ≤ 2.0%, Si ≤ 1.0%, C ≤ 0.30%, S ≤ 0.025% |
| Outer Diameter (OD) | 6.0 mm – 108.0 mm (custom sizes available) |
| Wall Thickness | 0.5 mm – 12.0 mm |
| Coil Diameter | Standard: 800 mm – 1200 mm (adjustable per order) |
| Coil Weight | Up to 2,500 kg per coil |
| Surface Finish | Pickled & passivated, bright annealed, or custom finish |
| Tensile Strength | ≥ 585 MPa (cold worked condition) |
| Yield Strength | ≥ 275 MPa (0.2% offset) |
| Elongation | ≥ 35% |
| Hardness | ≤ 95 HRB (annealed); ≤ 100 HRB (cold worked) |
| Operating Temperature | -196°C to +450°C |
| Standards | ASTM B151 / ASME SA-151 / EN 10217-7 / GB/T 20878 |
Manufacturing Process
The Monel 400 coil tube is manufactured through a rigorous multi-stage process ensuring dimensional accuracy, metallurgical integrity, and corrosion resistance:
- Ingot Casting: High-purity nickel-copper ingots are produced via vacuum induction melting (VIM) or AOD (Argon Oxygen Decarburization) processes to ensure tight chemical composition control and minimal impurity content.
- Hot Rolling & Extrusion: Cast ingots are reheated and hot-rolled into strip or hot-extruded into tube blanks, establishing the initial grain structure and dimensional profile.
- Cold Drawing: The tube blanks are cold-drawn through precision tungsten carbide dies to achieve the final outer diameter and wall thickness specifications with tight tolerances (±0.05 mm OD, ±10% wall thickness).
- Continuous Coiling: The drawn tubing is wound onto large-diameter coils using CNC-controlled winding equipment, ensuring uniform tension and minimal surface damage.
- Pickling & Passivation: Coils undergo acid pickling and passivation treatment to remove surface oxides, scale, and contaminants, restoring the alloy's full corrosion resistance.
- Quality Inspection: Every coil undergoes 100% dimensional verification, hydrostatic pressure testing, and spectroscopic chemical analysis before shipment.
Applications
Monel 400 coil tubes are specified for the most corrosive service conditions across multiple industries:
- Offshore & Marine Platforms: Seawater cooling systems, ballast water circuits, desalination plant heat exchangers, and subsea production equipment where chloride-induced corrosion is a primary concern.
- HF Acid Alkylation Units: Hydrofluoric acid alkylation reactors, acid transfer piping, and heat exchangers in petrochemical refining where resistance to anhydrous and aqueous HF is critical.
- Evaporators & Distillation Systems: Multiple-effect evaporators processing acidic brines, alkaline waste streams, and chemical concentrates in pharmaceutical and specialty chemical manufacturing.
- Petrochemical Processing: Acid gas treating units, amine scrubbing systems, and sour water handling equipment exposed to hydrogen sulfide and carbon dioxide.
- Power Generation: Condenser tubes and feedwater systems in coastal power plants subject to marine atmospheric corrosion.
- Pulp & Paper Industry: Digesters, bleach plants, and black liquor concentration systems involving hot caustic and acidic environments.
Quality Certifications & Compliance
Wenzhou Jixing Metal Materials Co., Ltd. maintains comprehensive quality assurance systems to ensure every Monel 400 coil tube meets or exceeds international standards:
- ISO 9001:2015 — Certified Quality Management System for consistent production quality
- ISO 14001:2015 — Environmental Management System for sustainable manufacturing practices
- ASTM / ASME Compliance — Full compliance with ASTM B151 and ASME SA-151 specifications for nickel alloy tubes
- Mill Test Certificates (MTC) — EN 10204 Type 3.1 certificates provided with every shipment, including chemical analysis, mechanical test results, and traceability documentation
- NDT Inspection — Available upon request: eddy current testing, ultrasonic inspection, and leak testing per ASTM E309 and ASME BPV Section V
- Material Traceability — Full heat lot traceability from raw material ingot through final coil shipment
Why Choose Wenzhou Jixing Monel 400 Coil Tubes?
With decades of expertise in specialty alloy coil tube manufacturing, Wenzhou Jixing delivers Monel 400 products that combine precise dimensional control, verified metallurgical quality, and proven field performance in the world's most corrosive environments. Our continuous coil format maximizes fabrication efficiency while our rigorous quality protocols ensure zero-compromise performance for critical process applications.