Inconel 718 is a precipitation hardening nickel-chromium alloy that also contains additions of iron, niobium, molybdenum, aluminium and titanium, providing a unique combination of high strength and corrosion resistance together with excellent weldability.
The alloy possesses excellent tensile, fatigue, creep and rupture strengths across a wide temperature range from around -253ºC to 705ºC. The high chromium content present in the material results in excellent oxidation resistance up to temperatures of around 980ºC.
Alloy 718 also offers outstanding corrosion resistance in a variety of media. It excels in many environments including organic and inorganic acids (other than when strongly oxidising), hydrogen sulphide and sour gasses. It is also especially resistant to chloride stress-corrosion cracking. This combination of properties, coupled with its exceptional weldability results in a material that truly can be described as a “Superalloy”.
SPECIFICATION OF INCONEL 718:
• UNS N07718
• ASTM /ASME B 366
CHARACTERISTICS OF INCONEL 718:
- Excellent tensile, fatigue, creep and rupture strengths across a wide temperature range from around -253ºC to 705ºC
- Outstanding corrosion resistance in many environments including organic and inorganic acids, other than when strongly oxidising, hydrogen sulphide and sour gasses
- Especially resistant to chloride stress-corrosion cracking
CHEMICAL COMPOSITION OF INCONEL 718:
|
Alloy
|
% |
Ni |
Cr |
Fe |
Mo |
Nb |
Co |
C |
Mn |
Si |
S |
Cu |
Al |
Ti |
|
718 |
Min. |
50 |
17 |
balance |
2.8 |
4.75 |
|
|
|
|
|
|
0.2 |
0.7 |
|
Max. |
55 |
21 |
3.3 |
5.5 |
1 |
0.08 |
0.35 |
0.35 |
0.01 |
0.3 |
0.8 |
1.15 |
MECHANICAL PROPERTIES OF INCONEL 718:
| Tensile Strength (N/mm2) | Proof Strees (N/mm²) | Elongation(%) | Hardness (HB) |
| 1034 | 827 | 17 | 313-354 |