MA718
Ni-19Cr-19Fe-3Mo-0.9Ti-0.5Al-5.1(Nb+Ta) (mass%)
Age-hardenable alloy with excellent strength up to 700°C mainly used for gas turbines.
Aerospace & Energy Materials Dept.
Main Features
MA718 is a nickel base precipitation-enhanced type alloy, which has good creep strength and high-temperature strength up to 700.Since it also has excellent workability, weldability, and toughness in low temperatures, the alloy has a wide range of application and is used for gas turbines, aircraft components, spring parts for rockets, and parts used in low temperatures, etc.
Weldability/Workability
Arc welding and resistance welding are both possible under solid solution condition and aging condition, though aging is recommended to be done after welding. The heating and cooling during welding interfere with the hardening due to its slow aging precipitation property.
Available Product Forms
Various shapes, such as flat-rolled plates, forgings, welding wires, wires, welded pipes and tubes, seamless pipes and tubes can be manufactured.
Specifications
Information on specifications to which MA718 alloy can be ordered.
ASTM UNS N07718
| Plates | Bars, Forgings |
|---|---|
| B670 | B637 |
ASME UNS N07718
| Bars, Forgings |
|---|
| SB-637 |
JIS NCF718
| Plates | Bars |
|---|---|
| G4902 | G4901 |
AMS UNS N07718
| Plates | Bars, Forgings | Pipes and tubes |
|---|---|---|
| 5596 | 5662 | 5589 |
| 5597 | 5663 | 5590 |
| 5664 |
Mechanical Properties
Tensile properties in room temperature and high temperature
| Heat treatment conditions | Testing temperature°C | Tensile strength N/mm2 | Yield strength (0.2% expansion) N/mm2 |
Elongation(%) |
|---|---|---|---|---|
| 925°C-1010°C WQ +720°CX 8hrs FC620°C X hr AC(Total 18hours) |
-196 Room temperature 538 649 760 |
1640 1380 1200 1100 850 |
1195 1155 1020 960 795 |
26 24 20 20 35 |
Stress rupture strength (N/mm2) for each temperature (100hrs and 1000hrs)
| 649°C | 760°C | |
|---|---|---|
| 100hrs | 723.7 | 303.0 |
| 1000hrs | 593.3 | >193.2 |
Impact value J (kgf•M)
| Charpy keyhole | Charpy V-notch | |
|---|---|---|
| -196°C | 21.7(2.22) | 27.9(2.85) |
| Room temperature | 18.8(1.92) | 25.5(2.60) |