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 1021 – 1052°C. Age hardening at 774 – 802°C.
Weldability
Very good.
Chemical Composition (Spesific for Bars)
Weight % | C | Mn | P | S | Si | Cr | Ni | Mo | Cu | Nb+Ta | Co | Fe | Al | Ti | B | Pb | Se | Bi |
Min. | 17,0 | 50,0 | 2,80 | 4,87 | bal. | 0,40 | 0,80 | |||||||||||
Max. | 0,045 | 0,35 | 0,010 | 0,010 | 0,35 | 21,0 | 55,0 | 3,30 | 0,23 | 5,20 | 1,00 | bal. | 0,60 | 1,15 | 60 ppm | 10 ppm | 5 ppm | 0,5 ppm |
Reference Standards
General:
- PED 2014/68/EU Annex I section 4.3
- NACE MR0175/ ISO 15156-3 and NACE MR0103/ ISO 17945
Bars:
-
API 6ACRA
Mechanical Properties (Specific for Bars – 120K)
Dimension (mm) |
Yield strength Rp0.2, MPa |
Tensile strength Rm, MPa |
Elongation [%] |
Hardness [HRC] |
Impact Charpy-V, -60ºC [J] |
< 76 | 827 – 1000 | ≥ 1034 | ≥ 20 | 32 – 40 | ≥ 68 |
76 – 254 | 827 – 1000 | ≥ 1034 | ≥ 20 | 32 – 40 | ≥ 47 |
> 254 | 827 – 1000 | ≥ 1034 | ≥ 20 | 32 – 40 | ≥ 41 |
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 – 120K