UNS N07718 is also known as UNS NO7718,UNS N07718, W.N.2.4668, NiCr19Fe19Nb5,GH4169 (China), Inconel 718
UNS N07718 is a Ni-Cr-Fe base precipitation-hardening deformed superalloy with a long-term operating temperature range of -253℃~650℃ and a short-term operating temperature of 800℃. The alloy has high strength below 650℃ and has good fatigue resistance, radiation resistance, oxidation resistance and corrosion resistance, as well as good processability, weldability and long-term structural stability. Suitable for the manufacture of turbine discs, rings, blades, shafts, fasteners and elastic components, plate structural parts, casing and so on in aviation, aerospace, nuclear energy and petrochemical industries. Alloy composition is divided into ordinary and high quality, high-quality UNS N07718 alloy carbon, niobium, sulfur and gas content control is more strict, mainly used for manufacturing all kinds of rotating parts.
Process Performance and Requirements
Vacuum Induction Furnace(VIM) and Electroslag Remelting Furnace(ESR)
- Product Chemical Composition
| Alloy | % | Ni | Cr | Fe | Mo | Ni | Co | C | Mn | Si | S | Cu | Al | Ti |
| UNS N07718 | Min | 50 | 17 | Rem | 2.8 | 4.75 | | | | | | | 0.20 | 0.65 |
| Max | 55 | 21 | | 3.3 | 5.50 | 1.0 | 0.08 | 0.35 | 0.35 | 0.015 | 0.30 | 0.80 | 1.15 |
- Product Physical Property
| Density | 8.24g/cm3 |
| Melting Point | 1260-1320℃ |
| Magnetic Energy | Nil |
- Product Mechanical Property
| Variety and Specification | Heat Treatment | Tensile Property | Hardness | Durability |
| MPa | MPa | % | MPa | r/h | % |
| Plate Sheet Strip | --- | Anneal | ≤895 | ≤485 | ≥40 | HRB≤ 94 | --- | --- | --- |
| ≤ 0.25 | Solid Solution | ≤965 | ≤550 | MV | HRB≤ 102 | --- | --- | --- |
| ＞ 0.25~4.75 | ≤965 | ≤550 | ≥30 | HRB≤ 102 | --- | --- | --- |
| ＞4.75~25 | ≤1035 | ≤725 | ≥30 | HRC≤ 25 | --- | --- | --- |
| ≤ 0.25 | Standard Heat Treatment | ≥1240 | ≥1035 | MV | HRC≤ 36 | --- | --- | --- |
| ＞0.25~25 | ≥1240 | ≥1035 | ≥12 | HRC≤ 36 | --- | --- | --- |
| ≤ 0.38 | ≥965 | ≥795 | ≥5 | --- | 655 | ≥23 | --- |
| ＞ 0.38~0.62 | ≥965 | ≥795 | ≥5 | --- | 655 | ≥23 | 4 |
| ＞ 0.62~25 | ≥1000 | ≥825 | ≥5 | --- | 690 | ≥23 | 4 |
| Standard Number | Variety | Heat Treatment | ℃ | Tensile Property |
| | MPa | MPa | % |
| Q/3B 4052 | Capillary Tube | Solid Solution | 20 | ≤ 1070 | ≤ 655 | ≥ 30 |
| Standard Heat Treatment | 20 | ≥ 1275 | ≥ 1035 | ≥ 12 |
| Remark: The whole tube tensile specimen is used |
| Standard Number | Variety | Heat Treatment | ℃ | Tensile Property | Hardness | Durability |
| MPa | MPa | % | % | MPa | r/h | % |
| GJB 2611A | Cold Drawn Rod | Standard Heat Treatment | 20 | ≥ 1270 | ≥ 1030 | ≥ 12 | ≥ 15 | HBW≥ 345 | --- | --- | --- |
| 650 | ≥ 1000 | ≥ 860 | ≥ 12 | ≥ 18 | --- | 690 | ≥ 23 | ≥ 4 |
| GJB 3527 | Cold Drawn Wire for Springs | 20 | ≥ 1270 | ≥ 1035 | ≥ 12 | -- | HBC≥ 32 | --- | --- | --- |
Wire
955℃±10℃x1h/AC+720℃士10℃x8h/FC(50℃士10℃/h)→620℃±5℃×(7`8)h/ AC,HRC≥32;
Rods and forgings,
(950~980)℃士10℃x1h/AC+720℃±5℃x8h/FC(50℃士10℃/h)→620℃±5℃ x8h/AC,HB≥346;
Plate and welding parts
Institution I:(940~960)℃/AC+(710~730)℃x(8~8.5)h/FC(50℃±10℃/h)→(615~620)℃x(8~8.5)h/AC,Solid Solution Holding time:(d)≤3mm,(25~30)min;(d)3mm~5mm,(30~35)min;
Tube
955℃士10℃x30min/AC(or air cooled)+720℃±10℃x8h/FC(50℃±10℃/h)→620℃±10℃.Make the total holding time not less than 18h, air cooled or forced air cooled
Direct aging treatment for Disc forgings:720℃士10℃x8h/FC(50℃±10℃/h)→620℃±10℃x8h/AC
Direct aging treatment for Disc forgings:720℃士10℃x8h/FC(50℃±10℃/h)→620℃±10℃x8h/AC
| Cold-drawn Wire | ¢0.3~¢18mm(Delivery in rolls or trays) |
| Hot-Rolling Wire | ¢5.5~¢20mm(Delivery in rolls) |
| Strip | thickness 0.1~4.5*width 6~350mm(Supply in rolls or straight strips) |
| Smooth Forged Rod on a Lathe | ¢60~350mm,L800-2500mm |
| Hot-rolled Burnishing | ¢20~80mm,L1000-5000mm |
| Cold Drawn and Burnishing | ¢2.5~18mm,L1000-8000mm |
| Seamless Tube | ¢1~275mm,wall thickness 0.2~30,L1000-8000mm |
