Inconel Vs Monel

Inconel vs Monel

Both Inconel and monel are nickel containing alloys. However, in addition to containing nickel as their primary alloyant, they also include other elements as their secondary alloyant. For instance, Monel alloys consist of copper, which ranges between 30% to 40% of their total weight. Whereas Inconel alloys contain chromium as their secondary alloyant.  In terms of their performance, monel rates as a mid performance alloy in comparison to nickel containing Inconel alloy, which is a high performance type. Several Inconel alloys are also referred to as superalloys because of their outstanding resistance to corrosion in addition to their ability to outperform several conventional alloys at elevated temperatures. Monel is a solid-solution binary metal, whereas Inconel is an austenitic superalloy.

Inconel vs Monel price

In comparison to monel, the price of Inconel is very high. The inclusion of high contents of nickel and chromium in its alloy makes the metal expensive. Since both alloys contain nickel, they are much more expensive in comparison to stainless steel alloys. However, market volatility combined with the fact that nickel is a commodity metal makes them expensive. And as the content of nickel is higher in some Inconel alloys, the cost of these alloys would be higher than some monel alloys.

Nickel content in Inconel and Monel

Both types of alloys have multiple grades that fall under them. The difference in their chemical composition led to their grading. This being said, the content of nickel in Inconel alloys varies between 44.2% to more than 72%. Though the composition would depend on the addition of nickel. For instance, Inconel 600 contains more than 72% nickel, whereas grade 617 contains nickel between 44.2% – 61%. On the other hand, the content of nickel in Monel alloys ranges anywhere between 52% to 67%, which is also why they cost lesser than Inconel alloys.

Difference between Inconel and Monel corrosion resistance

While both alloys have excellent corrosion resistance properties, the copper content in monel gives them outstanding resistance to seawater or salt sprays. Though Inconel alloys also have the ability to resist seawater, it is too expensive for use in marine engineering applications. However, because it has a higher content of nickel, Inconel alloys are able to withstand elevated temperature settings, which is not a feat that is achieved by monel alloys. Monel grades have limited tolerance to elevated temperature. In addition to marine environments, monel alloys are useful in environments that contain both hydrofluoric and sulfuric acids. Furthermore, they have the capacity to resist alkalies and harsher acids as well. Inconel alloys are great at parrying corrosion by oxidation.

Inconel and Monel alloy melting point

Since Inconel and monel are alloys, they do not have a specific melting point, but a melting range. The melting range of Inconel alloys is between a temperature range of 2500 - 2600°F, whereas Monel melts between a temperature range of 2372 - 2462°F.

Inconel and Monel density

The density of Monel is valued at 8.8 gm/cm3, whereas Inconel, which is lighter than monel is valued at 8.22 g/cm3

Monel and Inconel heat treatment

Inconel is generally treated by solution annealing in combination with aging. This combination is considered ideal because the mechanical properties and stress rupture properties of the alloys see a noticeable improvement. Monel, on the other hand, undergoes heat treatment by means of annealing.

The difference between Inconel and Monel hardness

The hardness of both alloys varies in different conditions. For instance, the hardness of monel in an annealed condition is lower in comparison to either hot finished condition or in a cold drawn condition. It is the same for Inconel alloys as well. However, compared to Inconel alloys, the hardness for monel is much lower.

Inconel and Monel temperature range

Although monel alloys are functional at sub-zero temperatures, these alloys cannot be used beyond elevated temperatures of 1000° F. Similar to monel, Inconel alloys deliver a good performance at low temperatures. However, due to a higher content of nickel in their alloys, most Inconels function well at elevated temperatures that range between 1200° F to about 2200° F, which is almost twice that of monel alloys.

Inconel and Monel yield strength

The yield strength of monel is lower than Inconel alloys. For instance, the yield strength of monel 400 offset at 0.2% is about 40Ksi, while the value for Inconel 625 stands at 65Ksi.

Inconel Chemical Composition

Grade Element (% by mass)
Ni Cr Fe Mo Nb Co Mn Cu Al Ti Si C S P B
600 72.0 14.0–17.0 6.0–10.0 1.0 0.5 0.5 0.15 0.015
617 44.2–56.0 20.0–24.0 3.0 8.0–10.0 10.0–15.0 0.5 0.5 0.8–1.5 0.6 0.5 0.15 0.015 0.015 0.006
625 58.0 20.0–23.0 5.0 8.0–10.0 3.15–4.15 1.0 0.5 0.4 0.4 0.5 0.1 0.015 0.015
690 59.5 30 9.2 0.35 0.01 0.02 0.35 0.019 0.003
718 50.0–55.0 17.0–21.0 balance 2.8–3.3 4.75–5.5 1.0 0.35 0.2–0.8 0.65–1.15 0.3 0.35 0.08 0.015 0.015 0.006
X-750 70.0 14.0–17.0 5.0–9.0 0.7–1.2 1.0 1.0 0.5 0.4–1.0 2.25–2.75 0.5 0.08 0.01

Inconel Equivalent material

STANDARD WERKSTOFF NR. UNS GOST AFNOR JIS BS EN OR
Inconel 600 2.4816 N06600 МНЖМц 28-2,5-1,5 NC15FE11M NCF 600 NA 13 NiCr15Fe ЭИ868
Inconel 601 2.4851 N06601 XH60BT NC23FeA NCF 601 NA 49 NiCr23Fe ЭИ868
Inconel 617 2.4663 N06617            
Inconel 625 2.4856 N06625 ХН75МБТЮ NC22DNB4M NCF 625 NA 21 NiCr22Mo9Nb ЭИ602
Inconel 690 2.4642 N06690            
Inconel 718 2.4668 N07718            
Inconel 725 - N07725            
Inconel X-750 2.4669 N07750            

Inconel mechanical properties

  Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation
600 8.47 g/cm3 1413 °C (2580 °F) Psi – 95,000 , MPa – 655 Psi – 45,000 , MPa – 310 40 %
601 8.1 g/cm3 1411 °C (2571 °F) Psi – 80,000 , MPa – 550 Psi – 30,000 , MPa – 205 30 %
617 8.3g/cm³ 1363°C ≥ 485 MPa ≥ 275 MPa 25 %
625 8.4 g/cm3 1350 °C (2460 °F) Psi – 135,000 , MPa – 930 Psi – 75,000 , MPa – 517 42.5 %
690 8.3g/cm³ 1363°C ≥ 485 MPa ≥ 275 MPa 25 %
718 8.2 g/cm3 1350 °C (2460 °F) Psi – 135,000 , MPa – 930 Psi – 70,000 , MPa – 482 45 %
725 8.31 g/cm3 1271°C-1343 °C 1137 MPa 827 MPa 20 %
X-750 8.28 g/cm3 1430°C 1267 MPa 868 MPa 25 %

Monel material equivalent

STANDARD WERKSTOFF NR. UNS GOST AFNOR JIS BS EN
Monel 400 2.4360 N04400 МНЖМц 28-2,5-1,5 NU-30M NW 4400 NA 13 NiCu30Fe
Monel 404 2.4867 N04404          
Monel 405   N04404          
Monel K500 2.4375 N05500          

Monel chemical composition

Trade Name ASTM/AISI

Alloy type

 UNS %Cu %Al %Ti %Fe %Mn %Si %Ni
Monel 400 B 127, B 164 N04400 28-34 2.5 max 2.0 max 0.5 max 63 min
Monel 401 N04401 28-34 2.5 max 2.0 max 63 min
Monel 404 N04404 Rem 0.05 max 0.5 max 0.1 max 0.1 max 52-57
Monel K-500 B 865 N05500 27-33 2.3-3.15 0.35-0.85 2.0 max 1.5 max 0.5 max 63 min
Monel 405 B 164 N04405 28-34 2.5 max 2.0 max 0.5 max 63 min

Monel mechanical properties

  Density Melting Point Tensile Strength Yield Strength (0.2%Offset) Elongation
Monel 400 8.8 g/cm3 1350 °C (2460 °F) Psi – 80000 , MPa – 550 Psi – 35000 , MPa – 240 40 %
Monel 404 8.91 gm/cm3 1300 - 1350℃ 70 KSI min (483 MPA min) 25 KSI min (172 MPA min) 35 %
Monel 405 8.80 g/cm3 1300 - 1350°C 550 Mpa 240 Mpa 40 %
Monel K500 8.44 g/cm3 1350 °C (2460 °F) Psi – 160000 , MPa – 1100 Psi – 115000 , MPa – 790 20 %

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