Difference Between Inconel 600 and 625

The fundamental difference

Both Monel and Inconel have nickel as their primary metal. However, Monel has copper and Inconel has Chromium.

To better distinguish the difference between these two, we need to address the strength of their dual-primary ingredient.

Inconel

Inconel® is a registered trademark (of Special Metals Corporation) referring to a family of austenitic nickel-chromium super alloys. Inconel® is a material that is specifically optimized for some of the toughest use conditions to be found in manufacturing while Titanium is a chemical element with symbol Ti and atomic number 22. It is a lustrous transition metal with a silver color, low density, and high strength.

Inconel Material Specification

  • Inconel 600
    Solid solution strengthened.
  • Inconel 601
  • Inconel 625
    Acid resistant, good weldability. The LCF version is typically used in bellows. Ideal for hardware and components in the power, aerospace and chemical processing industries. Offered in sheet, plate, bar and forgings.
  • Inconel 718
    Gamma double prime strengthened with good weldability. The preferred material for cryogenic storage tanks, turbines, downhole shafts and wellhead parts offered in sheet, plate and bar.
  • Inconel X750
    Commonly used for gas turbine components, including blades, seals and rotors.
  • Inconel 907
  • Inconel 909
  • Inconel 706
  • Inconel 617
  • Inconel 751
    Increased aluminium content for improved rupture strength in the 1600 °F range.
  • Inconel 792
    Increased aluminium content for improved high temperature corrosion properties, used especially in gas turbines.
  • Inconel 939
    Gamma prime strengthened to increase weldability.
  • Inconel 188
    Readily fabricated for commercial gas turbine and aerospace applications. Offered in sheet, plate and bar.
  • Inconel 690
    Low cobalt content for nuclear applications, and low resistivity.
  • Inconel 713C
    Precipitation hardenable nickel-chromium base cast alloy.
  • Inconel 230
    Inconel 230 Plate & Sheet mainly used by the power, aerospace, chemical processing and industrial heating industries, Aerospace Materials.

Inconel Composition

Inconel 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 alloys

Alloys of inconel include:

  • Inconel 600: Solid solution strengthened
  • Inconel 601
  • Inconel 625: Acid resistant, good weldability. The LCF version is typically used in bellows.
  • Inconel 690: Low cobalt content for nuclear applications, and low resistivity
  • Inconel 713C: Precipitation hardenable nickel-chromium base cast alloy
  • Inconel 718: Gamma double prime strengthened with good weldability
  • Inconel 751: Increased aluminium content for improved rupture strength in the 1600 °F range
  • Inconel 792: Increased aluminium content for improved high temperature corrosion properties, used especially in gas turbines
  • Inconel 939: Gamma prime strengthened to increase weldability

Inconel Equivalent Grades

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 Melting Point, Density and Tensile Strength

  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

Monel is a group of nickel alloys, primarily composed of nickel (up to 67%) and copper, with small amounts of iron, manganese, carbon, and silicon. Stronger than pure nickel, Monel alloys are resistant to corrosion by many agents, including rapidly flowing seawater. They can be fabricated readily by hot- and cold-working, machining, and welding. Monel® alloys are nickel-based alloys that contain between 29 and 33 percent copper.

Monel Alloys

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 Melting Point, Density and Tensile Strength

  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 %

Monel Equivalent Grades

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