Alloy 718 / UNS N07718
MATERIAL DESCRIPTION
Alloy 718 is a age-hardened nickel-chromium alloy containing also significant amounts of iron, niobium and molybdenum along with lesser amounts of aluminum and titanium. This provides a high strength alloy combined with corrosion resistance. Service temperatures range from -250°C to about 650°C. This alloy has also very good weld ability.
Applications
Used in pumps, tooling, gas turbines, rocket motors and nuclear reactors.
Heat Treatment
Solution annealed at 1000 – 1052°C. Age hardening at 774 – 802°C.
Weldability
Very good.
Chemical composition
| Weight % | C | SI | MN | S | P | CR | NI | MO | NB+TA | CU | TI | AL |
| MIN. | 17,00 | 50,00 | 2,80 | 4,75 | 0,65 | 0,20 | ||||||
| MAX. | 0,08 | 0,35 | 0,35 | 0,015 | 0,015 | 21,00 | 55,00 | 3,30 | 5,50 | 0,30 | 1,05 | 0,80 |
Product Standards: ASTM B637, EN 17752, AMS 5662, NACE MR0175
Mechanical properties
| Yield strength RP0.2, MPA |
Tensile strength RM, MPA |
Elongation [%] |
Hardness [HB] |
Impact, Charpy-V, -101ºC [J] |
| 725 – 1000 | 895 – 1250 | ≥ 30 | 248 – 363 | ≥ 27 |
Round bar stock
| DIA | KG/M |
| 12,7 mm | 1.1 |
| 25,4 mm | 4.4 |
| 31,875 mm | 6.9 |
| 38,1 mm | 1. |
| 41,2 mm | 11.5 |
| 45 mm | 13.8 |
| 50,8 mm | 18. |
| 63,5 mm | 27.5 |
| 76,2 mm | 39.4 |
| 90 mm | 55.1 |
| 101,6 mm | 70.2 |
| 127 mm | 110. |
| 152 mm | 158 |
| 165 mm | 186 |
| 177,8 mm | 215 |
| 203,2 mm | 281 |
| 215,9 mm | 289 |
| 230 mm | 360 |
| 254 mm | 439 |
| 304,8 mm | 632 |
Equivalent standards
- EN 2.4668
- UNS N07718
- Alloy 718