What is Monel 400 & K500?
Monel 400 is a nickel-copper alloy known for its excellent corrosion resistance in a wide range of environments, including seawater and acidic conditions. It maintains its strength across a wide temperature range and is highly resistant to chloride ion stress-corrosion cracking. Monel K500 is a precipitation-hardenable nickel-copper alloy that combines the excellent corrosion resistance of Monel 400 with the added advantage of higher strength and hardness. Its unique age-hardening properties make it ideal for various demanding applications where both corrosion resistance and mechanical strength are critical.
Monel 400
Nickel (Ni)
Copper (Cu)
Iron (Fe) Max
Manganese (Mn) Max
Carbon (C) Max
Silicon (Si) Max
Sulfur (S) Max
Monel K500
Nickel (Ni)
Copper (Cu)
Aluminum (Al)
Titanium (Ti)
Iron (Fe) Max
Manganese (Mn) Max
Carbon (C) Max
Silicon (Si) Max
Sulfur (S) Max
Types of Monel 400 & K500 Pipes & Tubes
As premier manufacturers in the industry, we specialize in producing both Monel 400/K500 seamless pipes & tubes and Monel 400/K500 welded pipes & tubes, offering comprehensive solutions for diverse industrial requirements in marine, chemical processing, and oil & gas applications.
Manufactured from solid billets through an extrusion process, these pipes deliver superior strength and exceptional pressure resistance. Seamless construction eliminates weld seams, making them the preferred choice for critical applications involving high-pressure systems, marine environments, and aggressive corrosive conditions where welding integrity is paramount. Their homogeneous structure ensures consistent performance in demanding service conditions.
These pipes provide an economical alternative with availability across a broader spectrum of sizes and dimensions. Welded pipes excel in structural applications, heat exchangers, and general corrosive service conditions where reliable welded joints are essential. Their cost-effectiveness makes them ideal for projects with budget constraints without compromising the excellent corrosion resistance properties that Monel alloys are known for.
400/K500 MONEL PIPES AND TUBES EQUIVALENT GRADES
| STANDARD | UNS | WNR. | EN | JIS | GOST | AFNOR | BS |
|---|---|---|---|---|---|---|---|
| Monel 400 | N04400 | 2.4360 | NiCu30Fe | NW 4400 | МНЖМц 28-2,5-1,5 | NU-30M | NA 13 |
| Monel K500 | N05500 | 2.4375 | – | – | – | – | – |
Specification of Monel Alloy 400/K500 Pipes and Tubes
| Specification | Details |
|---|---|
| Monel Seamless Pipes and Tubes | ASTM B165, B163 / ASME SB165, SB163 |
| Monel Welded Pipes and Tubes | ASTM B725 , ASME SB725 / ASTM B730, ASME SB730 |
| Pipe Size | Seamless 1/2″ – 10″ , Welded 1/2″ – 48″ |
| Tube Size | 4 to 219mm W. T.: 0.5 to 20mm |
| Schedule | SSCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH80, SCH120, SCH140, SCH160, XXS |
| Type | Seamless / ERW / Welded / Fabricated Pipes |
| Form | Round Pipes/Tubes, Square Pipes/Tubes, Rectangular Pipe/Tubes, Coiled Tubes, “U” Shape, Pan Cake Coils, Hydraulic Tubes |
| Length | Single Random, Double Random & Required Length |
| End | Plain End, Beveled End, Treaded |
| End Protection | Plastic Caps |
| Inspection, Test Reports | Mill Test Certificates, EN 10204 3.1, Chemical Reports, Mechanical Reports, PMI Test Reports, Visual Inspection Reports, Third Party Inspection Reports, NABL Approved Lab Reports, Destructive Test Report, Non Destructive Test Reports |
| Packing | Packed in Wooden Boxes, Plastic Bags, Steel Strips Bundled, or as per Customers Requests |
| Specials | Sizes and Specifications other than above can be manufactured on request |
CHEMICAL COMPOSITION OF MONEL 400/K500 SEAMLESS AND WELDED PIPES / TUBES
| Grade | Ni | Fe | C | Mn | Si | Cu | Al | Ti | S |
|---|---|---|---|---|---|---|---|---|---|
| 400 | 63.0-70.00 max | 2.50 max | 0.3 max | 2.00 max | 0.50 max | Remainder | – | – | 0.024 max |
| K500 | 63.0 min | 05 – 2 | 0.25 max | 1.5 max | 0.5 max | 27.0 – 33.0 | 2.3 – 3.15 | 0.35 – 0.85 | 0.010 max |
MECHANICAL PROPERTIES OF MONEL 400/K500 PIPES AND TUBES
| Grade | Tensile (ksi) | .2% Yield (ksi) | Elongation % | Hardness (HRb) |
|---|---|---|---|---|
| 400 | 75 to 90 | 25 to 50 | 60 to 35 | 60 to 80 |
| K500 | Psi – 1,60,000 , MPa – 1100 | Psi – 1,15,000 , MPa – 790 | 20 % | – |
PHYSICAL PROPERTIES OF MONEL 400 & K500 PIPES AND TUBES
| Property | Monel 400 | Monel K500 |
|---|---|---|
| Density | 0.318 lb/in³ (8.80 g/cm³) | 84.3 Kg.m⁻¹ (8.47 g/cm³) |
| Elastic/Young’s Modulus | 26.0 x 10⁶ psi @ 70°F (tension) | 179 x 10³ N/mm² (26 x 10⁶ psi) |
| Specific Heat | 0.102 Btu/lb/°F @ 70°F | 418 J.Kg⁻¹.°K⁻¹ @ 20°C |
| Melting Point | 2370°F to 2460°F (1300-1350°C) | 2400-2460°F (1315-1350°C) |
| Thermal Conductivity | 151 Btu • in/h/ft²/°F @ 70°F | 17.5 W.m⁻¹.°K⁻¹ @ 20°C |
| Electrical Resistivity | 0.511 μΩ • m @ 70°F | 0.62 μΩ.m @ 20°C |
| Magnetic Permeability | <1.005 @ 20°C | <1.005 @ 20°C |
| Curie Temperature | -90°C | -90°C |
| Mean Coefficient of Thermal Expansion | 13.9 x 10⁻⁶ °K⁻¹ (20-100°C) | 13.4 x 10⁻⁶ °K⁻¹ (20-100°C) |
| Tensile Strength | 70-85 ksi (480-585 MPa) | 110-130 ksi (760-895 MPa) |
| Yield Strength | 25-45 ksi (170-310 MPa) | 80-100 ksi (550-690 MPa) |
| Elongation | 35-60% | 20-30% |
💡 Practical Difference in Use
Use Monel 400 when: excellent corrosion resistance in seawater and acidic environments is needed, with good mechanical properties.
→ Example: marine components, chemical processing equipment, heat exchangers.
Use Monel K500 when: higher strength, hardness, and wear resistance are required along with corrosion resistance. → Example: pump shafts, valve components, marine fasteners, and oil well drill collars.
Uses of Monel 400/K500 Pipes and Tubes
The uses are defined by their exceptional corrosion resistance in seawater and acidic environments, combined with good mechanical properties across a wide temperature range.
- Marine and Offshore Applications: This is their primary function. Used for seawater piping systems, condenser tubes, heat exchangers, and various components exposed to saltwater environments.
- Chemical Processing Equipment: Ideal for handling acidic chemicals, solvents, and process streams where corrosion resistance is critical.
- High-Temperature and Pressure Systems: Both alloys maintain their strength and corrosion resistance at elevated temperatures, making them suitable for demanding industrial applications.
When to Choose Monel 400 vs. Monel K500?
This is a critical question. Monel 400 is the standard corrosion-resistant alloy, while Monel K500 offers enhanced mechanical properties through precipitation hardening.
Choose Monel 400 when:
- Excellent general corrosion resistance is the primary requirement
- Cost-effectiveness is important (Monel 400 is less expensive than K500)
- Applications involve seawater, acidic environments, or chemical processing
- Good mechanical properties are sufficient for the application
Upgrade to Monel K500 when:
- Higher strength and hardness are required
- Applications involve wear resistance and galling resistance
- Components need to withstand higher mechanical stresses
- Age-hardening properties can be utilized for enhanced performance
Industries That Use Monel 400/K500 Pipes and Tubes
These nickel-copper alloys are essential in industries requiring exceptional corrosion resistance in demanding environments. Here are the most prominent applications:
This is the largest consumer of Monel alloys due to their outstanding resistance to seawater corrosion.
Uses
Seawater piping systems, condenser tubes, heat exchangers, pump shafts, valve trim, and fasteners in marine environments.
Why Monel?
Superior resistance to seawater corrosion, biofouling, and stress-corrosion cracking in chloride environments.
Essential for handling corrosive chemicals and acids where stainless steels would fail.
Uses
Process piping for sulfuric, hydrochloric, and hydrofluoric acids, chemical reactors, and distillation columns.
Why Monel?
Excellent resistance to a wide range of acids, alkalis, and solvents at various concentrations and temperatures.
Critical for both upstream and downstream operations in corrosive environments.
Uses
Downhole instrumentation, wellhead components, production tubing, and processing equipment in sour gas service.
Why Monel?
Resists chloride stress-corrosion cracking and hydrogen sulfide attack in oil and gas production environments.
Used in various power generation applications requiring corrosion resistance.
Uses
Feedwater heaters, condenser tubes, boiler components, and nuclear power plant instrumentation.
Why Monel?
Excellent resistance to corrosion in high-purity water and steam systems, maintaining integrity under thermal cycling.
Essential for handling highly corrosive seawater and brine solutions.
Uses
Heat exchanger tubes, evaporator tubes, brine heaters, and piping systems in multi-stage flash and reverse osmosis plants.
Why Monel?
Superior resistance to pitting and crevice corrosion in high-chloride environments at elevated temperatures.
Used in critical applications requiring reliability in harsh environments.
Uses
Aircraft fuel and hydraulic lines, rocket components, naval ship systems, and submarine applications.
Why Monel?
Maintains mechanical properties at cryogenic temperatures and resists corrosion in various aerospace fluids.
Used in specific applications where corrosion resistance is paramount.
Uses
Process equipment, reaction vessels, and piping systems handling corrosive pharmaceutical intermediates.
Why Monel?
Resists corrosion from various organic and inorganic chemicals used in pharmaceutical manufacturing.
Essential for handling corrosive chemicals in paper manufacturing.
Uses
Digester components, bleaching equipment, and chemical recovery systems in kraft and sulfite pulp mills.
Why Monel?
Excellent resistance to corrosive pulping liquors, chlorides, and various bleaching chemicals.
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