Alloy X-750 (UNS N07750)
Age-hardenable nickel–chromium alloy for springs, fasteners and rotating hardware needing strength plus relaxation resistance.
- UNS
- N07750
- W.Nr / EN
- 2.4669
- Density
- 8.28 g/cm³
- Service range
- Cryogenic to ~700 °C (strength); ~980 °C (oxidation)
About Alloy X-750
Alloy X-750 is a gamma-prime strengthened variant of the nickel–chromium 600 system, hardened with titanium and aluminium. It offers high creep-rupture strength to about 700 °C and keeps useful spring properties and stress-relaxation resistance at temperatures where stainless spring materials fade.
The grade is also noted for retained toughness at cryogenic temperatures, which extends its use from hot-section hardware down to liquid-gas service. DMK Alloys supplies X-750 as bars, forged blanks and finished components, heat treated to the property level the application requires.
Alloy X-750 chemical composition (weight %)
| Element | Limit / range |
|---|---|
| Ni (+Co) | ≥ 70.0 |
| Cr | 14.0 – 17.0 |
| Fe | 5.0 – 9.0 |
| Ti | 2.25 – 2.75 |
| Al | 0.40 – 1.00 |
| Nb (+Ta) | 0.70 – 1.20 |
| Co | ≤ 1.0 |
| C | ≤ 0.08 |
| Mn | ≤ 1.0 |
| Si | ≤ 0.50 |
| Cu | ≤ 0.50 |
| S | ≤ 0.01 |
Composition limits per the commonly referenced standards listed below. Order-specific limits may differ — confirm against the governing specification.
Alloy X-750 mechanical properties (typical)
| Condition / form | Tensile, MPa | 0.2% Yield, MPa | Elongation, % |
|---|---|---|---|
| Bar, precipitation hardened, room temp. | 1120 – 1310 | 690 – 900 | 15 – 25 |
| Spring temper wire, aged | ≥ 1450 | — | — |
Values are typical or specification-minimum levels for guidance only — not a guarantee of properties. Certified values are established by testing against the ordered specification.
Alloy X-750 specifications & international equivalents
| System | Designation | Covers |
|---|---|---|
| UNS | N07750 | All product forms |
| AMS | AMS 5667 / 5668 / 5670 / 5671 | Bars, forgings |
| AMS | AMS 5598 | Sheet, strip, plate |
| AMS | AMS 5699 | Spring wire |
| ASTM | ASTM B637 | Bars, forgings |
| W.Nr / EN | 2.4669 · NiCr15Fe7TiAl | European cross-reference |
Cross-references are for guidance; the governing document is always the specification cited on your purchase order or drawing.
Alloy X-750 physical properties
| Property | Typical value |
|---|---|
| Density | 8.28 g/cm³ |
| Melting range | 1393 – 1427 °C |
| Modulus of elasticity (family-typical) | ≈ 200 – 220 GPa |
| Indicative service range | Cryogenic to ~700 °C (strength); ~980 °C (oxidation) |
Forms we manufacture
- Bars
- Forged blanks
- Rings
- Components to drawing
Dimensional ranges and delivery conditions are confirmed per enquiry.
Where Alloy X-750 earns its keep
Typically specified for:
- High-temperature springs
- Fasteners
- Turbine blades
- Wheels
- Extrusion dies
- Nuclear-reactor hardware
Also consider
Alloy 718
UNS N07718 · W.Nr 2.4668AMS 5662 / 5663 / 5664 · AMS 5596 / 5597
Precipitation-hardenable nickel–chromium superalloy — the workhorse grade for rotating and structural parts operating to ~700 °C.
Alloy 600
UNS N06600 · W.Nr 2.4816AMS 5665 · AMS 5540
The base nickel–chromium–iron engineering alloy: oxidation and chloride-cracking resistance across a very wide temperature span.
Alloy 80A
UNS N07080 · W.Nr 2.4952AMS 5766 · ASTM B637
The classic age-hardenable 80/20 nickel–chromium superalloy for blading and high-temperature fasteners.
Request Alloy X-750 to your specification
State the governing standard, form, dimensions, quantity and testing requirements — the export team responds with a manufacturer's quotation.