Looking for reliable Nickel Based Alloy manufacturers in China? You are in the right place. As a premier nickel based alloy factory with 20 years of experience, we offer factory-direct prices without middlemen for Monel 400 (UNS N04400) and other high temperature alloy, corrosion resistant alloy, Inconel, Incoloy, Hastelloy and Monel series products. In this guide, we explain what Monel 400 is used for across major industries, along with its chemical composition, mechanical properties, product forms, and corrosion resistance data to help you select the right material.
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Real Photos of Monel 400 Nickel Alloy Seamless Pipes / Tubes
What is Monel 400 (UNS N04400)?
Monel 400 is a nickel-copper alloy registered as UNS N04400 (W.Nr.2.4360, DIN NiCu30Fe). It is a solid-solution strengthened alloy containing approximately 63% nickel and 28–34% copper, with small amounts of iron and manganese. This nickel copper alloy derives its strength from solid-solution strengthening rather than precipitation hardening, meaning it retains mechanical properties across a wide temperature range from cryogenic to approximately 500°C.
As a corrosion resistant alloy, Monel 400 is renowned for its excellent resistance to seawater, hydrofluoric acid, sulfuric acid, and alkalis. It is widely specified in marine engineering, chemical processing, and oil and gas industries where other materials fail rapidly. The alloy conforms to ASTM B127 (plate), B165 (seamless pipe), B164 (bar), and B163 (condenser tube) standards.
Chemical Composition of Monel 400 (UNS N04400)
The chemical composition of Monel 400 is governed by ASTM B127 / B165 / B164 standards. Each heat is verified by OES analysis and documented on the EN 10204 3.1 Mill Test Certificate.
| Element | Content (wt%) |
|---|---|
| Ni | ≥63.0 |
| Cu | 28.0 – 34.0 |
| Fe | ≤2.5 |
| Mn | ≤2.0 |
| C | ≤0.30 |
| Si | ≤0.50 |
| S | ≤0.024 |
The high nickel content provides the alloy's excellent corrosion resistance and toughness, while copper contributes to seawater resistance. The low carbon content ensures good weldability without intergranular corrosion concerns in the heat-affected zone.
Mechanical Properties of Monel 400 Products
Monel 400 mechanical properties are tested per ASTM E8 on material in the annealed condition. All data below corresponds to specific Monel 400 heats and product forms, verified by mechanical test reports.
| Property | Typical Value (Annealed) |
|---|---|
| Tensile Strength, MPa | ≥480 |
| Yield Strength (0.2% Offset), MPa | ≥195 |
| Elongation (A50), % | ≥35 |
| Hardness, HB | 110 – 150 |
| Density, g/cm³ | 8.80 |
| Melting Range, °C | 1300 – 1350 |
| Magnetic Permeability | ≤1.001 (essentially non-magnetic) |
The Monel 400 density of 8.80 g/cm³ is slightly higher than pure nickel. The alloy remains essentially non-magnetic, which is advantageous in electronic and instrumentation applications. It maintains good ductility and toughness at cryogenic temperatures, making it suitable for liquefied natural gas (LNG) service.
Product Forms and Dimensions of Monel 400
Monel 400 is available in a full range of product forms to meet diverse industrial requirements:
- ✓ Monel 400 plate (ASTM B127): Thickness 1.0–80mm, width up to 2500mm
- ✓ Monel 400 sheet (ASTM B127): Thickness 0.3–4.0mm, cold rolled 2B finish
- ✓ Monel 400 seamless pipe (ASTM B165): OD 6–325mm, wall 1.0–25mm
- ✓ Monel 400 welded pipe (ASTM B725): OD up to 1220mm
- ✓ Monel 400 round bar (ASTM B164): Diameter 6–350mm, hot rolled / cold drawn
- ✓ Monel 400 tube (ASTM B163): Condenser and heat exchanger tube, OD 6–51mm
- ✓ Monel 400 fittings and forgings (ASTM B564): Elbows, tees, flanges, custom forgings
Delivery conditions include annealed, cold worked, hot rolled, and stress relieved, depending on product form and customer specification. Check our Monel 400 pipe and plate stock specifications for current inventory.
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Corrosion Resistance of Monel 400 Nickel Alloy
The primary reason Monel 400 is specified across industries is its exceptional corrosion resistance in specific media. In flowing seawater, Monel 400 demonstrates a very low corrosion rate - typically less than 0.025 mm/year - far outperforming copper-based alloys and stainless steels. It resists pitting, crevice corrosion, and stress-corrosion cracking in chloride environments.
Monel 400 also offers excellent resistance to hydrofluoric acid (HF) across a wide range of concentrations and temperatures, making it one of the few metallic materials suitable for HF service. It resists sulfuric acid at concentrations below 50% at room temperature, and provides good resistance to non-oxidizing acids, alkalis, and neutral salts.
However, Monel 400 should not be used in oxidizing acid environments (e.g., nitric acid) or in the presence of ferric or mercuric salts, which can cause rapid attack. In such environments, Hastelloy grades or other nickel based alloys are more appropriate.
Monel 400 vs Stainless Steel: When to Choose Which
A common question is whether Monel 400 is better than stainless steel. The answer depends on the service environment. In flowing seawater and chloride-rich media, Monel 400 dramatically outperforms 316 stainless steel, which suffers pitting and crevice corrosion in stagnant seawater. Monel 400 also resists stress-corrosion cracking where austenitic stainless steels are vulnerable.
In hydrofluoric and sulfuric acid service, Monel 400 is one of the few viable metallic options, while stainless steels are rapidly attacked. However, in oxidizing acid environments or high-temperature oxidizing atmospheres above 500°C, stainless steels such as 310S or nickel chromium alloys like Inconel 600 are superior choices. Monel 400 is also significantly more expensive than 316 SS, so it should be specified where its unique corrosion resistance justifies the cost.
What is Monel 400 Used For? Key Applications
Monel 400 is used across multiple industries where seawater corrosion resistance, acid resistance, and mechanical reliability are critical. The main application areas include:
- ✓ Marine engineering: Propeller shafts, pump shafts, seawater valves, heat exchanger tubes, offshore platform piping - Monel 400 for marine environments resists biofouling and chloride pitting
- ✓ Chemical processing: Hydrofluoric acid alkylation units, sulfuric acid vessels, process piping, reactor internals - Monel 400 for chemical industry handles reducing acid media
- ✓ Oil and gas: Downhole tools, instrument tubing, sour gas service components, heat exchangers - Monel 400 for oil and gas resists chloride SCC and H₂S environments
- ✓ Power generation: Steam generator tubes, feedwater heater tubing, boiler components - Monel 400 tube resists erosion-corrosion in high-velocity water
- ✓ LNG and cryogenic: Cryogenic piping, valve stems, LNG storage vessel components - Monel 400 retains toughness at −196°C
- ✓ Electronics and instruments: Non-magnetic components, electrical connectors, precision instrument parts
Monel 400 welding is performed using GTAW (TIG) and GMAW (MIG) processes with matching filler ERNiCu-7 (Monel 60). The alloy offers good weldability without preheat. Post-weld stress relief at 550–650°C may be recommended for highly stressed components to prevent stress-corrosion cracking in hydrofluoric acid service.
Monel 400 machining requires carbide tooling with reduced cutting speeds and adequate coolant flow, as the alloy tends to work-harden during machining. Proper tool geometry and chip control are essential for achieving good surface finish.
Why Choose GNEE Alloy as Your Monel 400 Supplier?
✅ Ready Stock & Inventory: We maintain over 500 tons of nickel alloy stock, including Monel 400 plate (ASTM B127), pipe (B165), bar (B164), and tube (B163) in standard dimensions. Standard stock ships in 7–10 business days; custom sizes ship in 25–30 business days. Mixed-grade container shipments supported with no mandatory large MOQs.
✅ Quality & Inspection: Every batch undergoes 100% full-item inspection - OES chemical analysis, mechanical testing (ASTM E8), 100% UT (ASTM E435), PMI material identification, and dimensional verification. Third-party inspection by SGS, BV, or TÜV available. All records archived for 5+ years.
✅ Material Certification: Every shipment includes EN 10204 3.1 MTC, with 3.2 third-party certificates on request. All products comply with ASTM B127 / B165 / B164 / B163 standards under our ISO 9001 quality system. Full traceability from heat number to final delivery.
✅ Export Packaging & Logistics: 4-layer oceanic packaging: VCI anti-rust paper, waterproof PE film, galvanized steel wrapping, and ISPM-15 fumigated pallets. Sea, rail, and air freight supported with pre-shipment loading photos.
✅ Responsive Customer Support: Technical team responds within 24 business hours, offering grade selection, welding, and custom cutting guidance. Orders range from 5kg samples to full container loads. Backed by 20 years of special alloy export experience serving 40+ countries.
Conclusion
Monel 400 (UNS N04400) is a versatile nickel-copper alloy used for marine engineering, chemical processing, oil and gas, power generation, and cryogenic applications. Its exceptional resistance to seawater, hydrofluoric acid, and chloride stress-corrosion cracking makes it a proven material for harsh service environments where stainless steels fail.
Whether you need Monel 400 plate, pipe, bar, or tube, we provide ASTM-certified products with full EN 10204 3.1 MTC, 100% UT, and third-party inspection support. Contact us for the latest Monel 400 price list and let our 20 years of nickel alloy expertise support your project.
FAQ:
1.Is Monel 400 the same as Alloy 400?
Yes, Monel 400 and Alloy 400 are the exact same material
2.What is the equivalent material for Monel 400?
Monel 400 (Alloy 400) is a nickel-copper alloy with standard global equivalents including UNS N04400, Werkstoff Number 2.4360, and ISO NiCu30Fe. It offers high strength and great resistance to seawater and acid.
3.What is the material N04400?
UNS N04400, widely known as Monel 400 or Alloy 400, is a high-strength, corrosion-resistant nickel-copper alloy composed of roughly 63% to 67% nickel and 28% to 34% copper.
4.Why is Monel so expensive?
Monel is expensive primarily because it consists of 60% to 70% nickel, combined with copper and small amounts of other metals, and nickel is one of the costliest and most volatile engineering metals on the market.
5.Is Monel 400 hard to machine?
Yes, Monel 400 is considered difficult and challenging to machine compared to ordinary carbon steels and aluminum, holding a low machinability rating of around 44% to 45%.
