


NACE 718 is a precipitation hardened nickel-chromium alloy. It combines high strength in the aged condition with good corrosion resistance and weldability. NACE 718 indicates material stocked in the heat treated condition and provides high strength while meeting the maximum hardness requirements of the NACE MR0175, MR0103 and ISO 15156-3 specifications for use in oil tools used for sour service.
NACE 718 is annealed between 1875-1925°F and water quenched. Subsequently it is aged in the range of 1425-1475°F for 6-8 hours and air cooled or faster to room temperature.
NACE 718 Round Bar
| Ni | Cr | Mo | Mn | Cu | Si | C | S | P | Co | Cb+Ta | Pb | Se | Bi | Mg | Ti | Al | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MIN | 50 | 17 | 2.8 | - | - | - | - | - | - | - | 4.87 | - | - | - | - | 0.8 | 0.4 | - |
| MAX | 55 | 21 | 3.3 | 0.35 | 0.23 | 0.35 | 0.045 | 0.01 | 0.01 | 1.0 | 5.2 | 1000 ppm |
0.0005 ppm |
50 ppm |
0.0006 ppm |
1.15 | 0.6 | Balance |
Density: 0.297 lb/inch3
Melting Point: 2160 - 2440°F
| Temperature, °F | 70 | 200 | 400 | 600 | 1000 | 1200 |
| Coefficient* of Thermal Expansion, in/in°F x 10-6 | - | 7.3 | 7.5 | 7.7 | 8.1 | 8.4 |
| Thermal Conductivity Btu • ft/ft2 • hr • °F |
6.4 | 7.2 | 8.2 | 9.3 | 11.3 | 12.3 |
| Modulus of Elasticity, Dynamic psi x 106 | 29.0 | 28.4 | 27.6 | 26.7 | 24.8 | 23.7 |
* 70°F to indicated temperature.
Minimum Specified Properties, API 6A 718 bar Solution Annealed And Aged Condition
| Minimum | Maximum | |
| Ultimate tensile strength, ksi | 150 | - |
| 0.2% yield strength, ksi | 125 | 145 |
| Elongation, % | 20% | - |
| Reduction of area, % | 35% | - |
| Impact Strength*Min average/ min single, ft-lbs |
40/35 | - |
| Hardness, Rockwell C | 32 | 40 |