Alloy 718 is a precipitation-hardening nickel-chromium alloy containing significant amounts of iron, columbium, and molybdenum, along with lesser amounts of aluminum and titanium. It is sometimes referred to as a “super alloy”.
718 is commonly used in High temperature bolts, nuts and fasteners, Airframe parts, Gas turbine engines, Cryogenic tanks and Nuclear engineering applications
Chemical Properties | ||
Element | min | max |
Carbon | — | 0.08 |
Manganese | — | 0.35 |
Silicon | — | 0.35 |
Phosphorus | — | 0.015 |
Sulfur | — | 0.015 |
Chromium | 17 | 21 |
Nickel | 50 | 55 |
Molybdenum | 2.8 | 3.3 |
Columbium (Niobium) | 4.75 | 5.5 |
Titanium | 0.65 | 1.15 |
Aluminum | 0.2 | 0.8 |
Cobalt | — | 1 |
Tantalum | — | 0.05 |
Boron | — | 0.006 |
Copper | — | 0.3 |
Iron | remainder | |
Tensile Properties | ||
Solution Heat Treated | ||
Tensile Strength, max | 155(KSI) | |
Yield Strength at 0.2% Offset, max | 95 (KSI) | |
Elongation in 2 Inches (50.8 mm), min | 30%ngth Super Alloy |
Other Common Applications of 718