718
High-Temp Steel718
Precipitation-hardening Ni-base superalloy, aerospace workhorse. (ASTM B637; equiv UNS N07718 / AMS 5662 / GB 0Cr17Ni21Mo10Nb). Nominal values—confirm mill certificate.
Chemical Composition (%)
| NI | 50 |
|---|---|
| CR | 17 |
| NB+TA | 4.75 |
| MO | 2.8 |
| TI | 0.65 |
| AL | 0.2 |
| C | 0.08 |
| MN | 0.35 |
| SI | 0.35 |
| P | 0.015 |
| S | 0.015 |
| B | 0.006 |
Mechanical Properties
Tensile:≥1275 MPa;Yield:≥1035 MPa;Elong:≥12%;Hardness:≥36 HRC
Chinese Standard
ASTM B637 718
Equivalent Standards
AMS 5662
Equivalent Grades
Machining is difficult — use ceramic/PCBN tools, generous coolant and rigid setups. Keep clean (vacuum/inert melting) to avoid inclusions; avoid contamination by low-melting elements.
Applications
沉淀硬化镍基，航空主力。,"Bar
Available Forms
Forging
Uses
Plate"
Heat Treatment
Nickel/cobalt-base superalloy retaining high strength, creep and corrosion resistance at extreme temperature. Used in gas-turbine blades, aero-engine hot sections, combustors and advanced energy systems.
Precautions
Solution treated 1050–1250 °C and aged (≈700–900 °C) to precipitate γ′/γ″ strengtheners; processed via vacuum induction + VAR/ESR for cleanliness.
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