Inconel Alloy Summary:
Inconel alloys are oxidation-corrosion-resistant materials well suited for service in extreme environments subjected to pressure and heat. When heated, Inconel forms a thick, stable, passivating oxide layer protecting the surface from further attack. Inconel retains strength over a wide temperature range, attractive for high-temperature applications where aluminum and steel would succumb to creep as a result of thermally induced crystal vacancies. Inconel's high-temperature strength is developed by solid solution strengthening or precipitation hardening, depending on the alloy.
Inconel Alloy Futures:
When determining strength, tensile strength, corrosion resistance, and even melt resistance can be measured. Inconel 625 has a high tensile strength range of 103 - 160 ksi compared to the 73.2 ksi of stainless steel and can maintain that strength at higher operating temperatures.
Though exact measurements vary, reported statistics state the range of the Inconel melting point between 2,350°F and 2,460°F (1,290°C and 1,350°C). While the Inconel melting point is lower than that of stainless steel, Inconel 625 is stronger than stainless steel at high temperatures while being more resistant to oxidation and scaling as well.
Inconel is considered a superalloy due to being well suited for extreme pressure and heat environments as well as being corrosion resistant. However, stainless steel alloys are often more suitable for sterile manufacturing or medical applications. A superalloy like Inconel tends to be better for heat treating applications and other high-temperature processes.
Inconel Alloy Valve Applications:
Inconel is ideally used in the oil and gas extraction industries due to its high temperature resistance and oxidation resistant properties. The oil and gas industries need a superalloy metal, like Inconel, that can withstand extreme environments and volatile, corrosive gasses.The superalloy Inconel 625 is especially useful for the processing systems required for natural gas production. Due to Inconel 625’s particularly strong thermal fatigue strength and oxidation resistance, it’s often used for the separation of extracted fluids or in line steel transfer piping.
Inconel is famously resistant to extreme temperatures, and retains enough tensile strength at high temperatures to continue holding moderate loads (Inconel 625 retains 13.3 ksi tensile strength at 2,000°F). This makes Inconel the ideal basket material for heat treat applications—comparing favorably to stainless steel alloys such as Grade 304, 316, and 330 SS.
Inconel is often used in marine applications because of its extraordinary resistance to sodium chloride (salt) at a variety of temperatures. So, for processes that use salt or factory locations near the ocean, Inconel can be ideal for a parts washing basket. Inconel is considered a superalloy due to being well suited for extreme pressure and heat environments as well as being corrosion resistant. However, stainless steel alloys are often more suitable for sterile manufacturing or medical applications. A superalloy like Inconel tends to be better for heat treating applications and other high-temperature processes.
Inconel Alloy Material Grades:
| Inconel |
Element, proportion by mass (%) |
| Ni |
Cr |
Fe |
Mo |
Nb & Ta |
Co |
Mn |
Cu |
Al |
Ti |
Si |
C |
S |
P |
B |
| 600 |
≥72.0 |
14.0–17.0 |
6.0–10.0 |
|
|
N/A |
≤1.0 |
≤0.5 |
|
|
≤0.5 |
≤0.15 |
≤0.015 |
|
|
| 617 |
44.2–61.0 |
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 |
0.05–0.15 |
≤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 |
≥58 |
27–31 |
7–11 |
|
|
|
≤0.50 |
≤0.50 |
|
|
≤0.50 |
≤0.05 |
≤0.015 |
|
|
| Nuclear grade 690 |
≥58 |
28–31 |
7–11 |
|
|
≤0.10 |
≤0.50 |
≤0.50 |
|
|
≤0.50 |
≤0.04 |
≤0.015 |
|
|
| 718 |
50.0–55.0 |
17.0–21.0 |
Balance |
2.8–3.3 |
4.75–5.5 |
≤1.0 |
≤0.35 |
≤0.3 |
0.2–0.8 |
0.65–1.15 |
≤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 |
|
|