NICKEL ALLOY 718 (Inconel® 718)
DESCRIPTION
Nickel Alloy 718 (Inconel 718®/UNS N07718) is a nickel-chromium alloy that was developed for the aerospace industry. However, its excellent strength and corrosion resistance were recognized by the oil industry, and it is now widely used in this field also. Nickel Alloy 718 is age-hardenable to give high tensile, fatigue, creep, and rupture strength, good corrosion resistance, ease of formability and excellent weldability.
PRODUCT FORM
Supra Alloys meets its customers’ specialty metal needs by offering Nickel Alloy 718 in the following product forms:
Nickel Alloy 718 Slit Coil (ASTM B637/AMS5662/AMS 5663)
Nickel Alloy 718 Cut-To-Length (ASTM B670/ASTM B906/AMS 5596/AMS 5950)
Nickel Alloy 718 Strip (ASTM B670/ASTM B906/AMS 5596/AMS 5950)
APPLICATION
High Temperature Alloys like Nickel Alloy 718 can be used in a number of different applications due to its strength, good corrosion resistance, ease of formability and weldability, as well as its ability to be heat-treated.
Aerospace and Power Generation:
When used in an aerospace and power generation application, Nickel Alloy 718 is age-hardened to give maximum strength and high creep resistance with typical hardness values exceeding 42HRC. Nickel Alloy 718 is mostly used in:
- Gas turbines
- Aircraft engines
- Fasteners
Oil Industry:
When used in the oil industry, Nickel Alloy 718 is age-hardened such that the hardness does not exceed 40HRC to prevent stress corrosion cracking. Nickel Alloy 718 is used within the oil industry for
- Valves
- Precision tubing.
Nuclear Power:
Nickel Alloy 718 is often used in nuclear power plant applications because of its good fatigue and rupture strength.
CHEMICAL COMPOSITION
The Chemical Composition of Nickel Alloy 718 is:
|
Element |
Content |
|
Carbon, C |
0.08 |
|
Silicon, Si |
0.35 |
|
Manganese, Mn |
0.35 |
|
Phosphorous, P |
0.015 |
|
Aluminum, Al |
0.8 |
|
Boron, B |
0.6 |
|
Cobalt, Co |
1.0 |
|
Chromium, Cr |
21.0 |
|
Copper, Cu |
0.3 |
|
Iron, Fe |
|
|
Molybdenum, Mo |
3.3 |
|
Niobium, Nb |
5.5 |
|
Nickel, Ni |
55.0 |
|
Titanium, Ti |
1.15 |
MECHANICAL PROPERTIES
The Mechanical Properties of Nickel Alloy 718 are:
|
Temper |
Solution-treated |
|
Tensile Rm |
155 ksi (max.) |
|
Tensile Rm |
1069 MPa (max.) |
|
R.p. 0.2% Yield |
95 ksi (max.) |
|
R.p. 0.2% Yield |
655 MPa (max.) |
|
Elongation (2” or 4D gl) |
30% (min.) |
PHYSICAL PROPERTIES
The physical properties of Nickel Alloy 718 are as follows:
|
Solution Treated |
Solution Treated and Aged |
|
|
Density |
0.296 lb/in3 (8.192 g/cm3) |
0.297 lb/in3 |
|
Specific Gravity |
8.19 |
8.22 |
|
Melting Range |
2500-2600°F |
1370-1430°C |
INCONEL is a trademark of the Special Metals Corporation group of companies.