Overview
Whether you are a Monel alloy supplier or a Monel alloy user, you will encounter a problem when replacing Monel materials or suggesting material selection to customers.
Should I choose Monel 400 or Monel K-500? Which scenes are they used in?
If you have the same confusion, you must read this article. It will let you understand all the same and different between Monel 400 and Monel K-500. It will be your compass when selecting materials.
Basic Information
Name
Monel 400
UNS N04400
W.Nr. 2.4360
Brand
MONEL®
Matrix
Type
Solid Solution
Strengthened Alloy
Density
8.80 g/cm³
Use Temperature
Room Temperature
Name
Monel K-500
UNS N05500
W.Nr. 2.4375
Brand
MONEL®
Matrix
Type
Precipitation
Strengthened Alloy
Density
8.44 g/cm³
Use Temperature
Room Temperature
Introduction
Monel 400
MONEL® nickel-copper alloy 400 (UNS N04400 / W.Nr. 2.4360 and 2.4361) is a solid-solution alloy that can be hardened only by cold working. It has high strength and toughness over a wide temperature rangeand excellent resistance to many corrosive environments.
Monel K-500
MONEL® alloy K-500 (UNS N05500 / W.Nr. 2.4375) is a nickel-copper alloy which combines the excellent corrosion resistance of MONEL alloy 400 with the added advantages of greater strength and hardness. The increased properties are obtained by adding aluminum and titanium to the nickel-copper base.
Chemical Composition
Purity
Monel 400
lose
Monel K-500
WIN
From the comparison of the chemical composition of Monel 400 and Monel K-500, it can be seen that Monel K-500 contains less impurity elements (sulfur and manganese) than Monel 400. Therefore, the relatively high purity of alloy K-500 also makes its various properties more superior than alloy 400.
Sulfur
The sulfur content of Monel 400 is below 0.024%. The sulfur content of Monel K-500 is below 0.010%. It makes K-500 have better tensile strength and durability than 400.
Manganese
The maximum manganese content of 400 alloy and K-500 alloy are 2.00% and 1.50%, respectively. This gap makes K-500 alloy have better durable strength.
Therefore, if your application requires the alloy to be under stress for a long time, it is recommended to choose K-500 alloy with better creep properties.
Corrosion Resistance
Monel 400
Tie
Monel K-500
Tie
Both Monel 400 alloy and Monel K-500 alloy contain a large amount of nickel and copper, and their specific gravity is basically the same.
A large amount of nickel and copper content makes both alloys have good corrosion resistance. Therefore, both of these alloys are commonly used in the seawater and chemical industries.
Mechanical Behavior
Monel 400
Toughness
Monel K-500
Strength
The 400 alloy is a solid solution strengthened single-phase alloy, while the K-500 alloy with aluminum and titanium added is a precipitation strengthened multi-phase alloy.
This essential difference makes K-500 superior to 400 alloy in various strength and hardness indicators.
In contrast, the toughness of alloy 400 is better than that of K-500.
If your product has higher requirements for strength and hardness, Monel K-500 alloy should be given priority.
If your product has higher requirements for toughness, Monel 400 alloy should be given priority.
Physical Properties
Monel 400
Magnetic
Monel K-500
Non-magnetic
The most important difference in physical properties between alloy 400 and alloy K-500 is magnetic properties.
400 alloy is magnetic at certain temperatures, and it is non-magnetic at other temperatures.
Although the K-500 alloy will produce a magnetic layer on the surface during processing, it will exhibit completely non-magnetic characteristics through pickling.
Therefore, if you require that the alloy is always non-magnetic during use, you should consider using Monel K-500.
The comparison of other physical properties between Monel 400 and Monel K-500 is as follows:
| Monel 400 | Monel K-500 | |
|---|---|---|
| Density, g/cm³ | 8.80 | 8.44 |
| Density, lb/in.³ | 0.318 | 0.305 |
| Melting Range, °F | 2370-2460 | 2400-2460 |
| Melting Range, °C | 1300-1350 | 1315-1350 |
| Tension | 26.0 | 26.0 |
| Compression | 26.0 | |
| Torsion | 9.5 | 9.5 |
| Poisson’s Ratio | 0.32 | 0.32(aged material) |
| Curie Temperature, °F | 70-120 | |
| Curie Temperature, °C | 21-49 |
Heat Treatment
Monel 400
Solution
Treatment
Monel K-500
Aging
Treatment
Due to the different strengthening mechanisms (400 is solid solution strengthening, K-500 is precipitation strengthening), 400 should be solid-solution treated during the final heat treatment to completely dissolve the solid solution strengthening elements into the alloy matrix. K-500 uses aging treatment in the final heat treatment to completely precipitate the precipitation strengthening phase to achieve the best strengthening effect.
Application
Monel 400 is mostly used for corrosion-resistant containers and connectors. While Monel K-500 is used in environments with high stress and high pressure.
Supported Products
Monel 400
Main Standards
Monel 400
Condenser and Heat Exchanger Tube: ASTM B163
Seamless Pipe and Tube: ASTM B165, ASTM B829
Welded Pipe: ASTM B725, ASTM B775
Welded Tube: ASTM B730, ASTM B751
Welded Fittings: ASTM B366
Rod, Bar, and Wire: ASTM B164
Forgings: ASTM B564
Plate, Sheet, and Strip: ASTM B127
Monel K-500
/
/
/
/
/
Rod and Bar: ASTM B865
/
/
Price
Monel 400
LOW
Monel K-500
high
K-500 has a higher degree of alloying (more alloying elements), higher deformation resistance and lower plasticity, which makes the production process more difficult.
This has led to an increase in the production cost of the K-500, so the price is also higher.
If your application does not need to consider higher strength and non-magnetic, you should prefer Monel 400 to reduce costs.
Conclusion
Monel 400 is a solid solution strengthened alloy, Monel K-500 is a precipitation strengthened alloy. The overall performance of K-500 is better than 400.
Both alloys have very good corrosion resistance.
Monel 400 is magnetic in some cases, and Monel K-500 is non-magnetic in any case.
If the performance is sufficient, it is recommended to choose Monel 400 to reduce costs.
AEETHER CO., LIMITED produce cost-effective Monel 400 and Monel K-500 products. If you have corresponding needs, please do not hesitate to contact us:
