- Grade / Alloy
- Alloy 751
- EN / W.Nr.
- 2.4694
- AISI / SAE
- —
- UNS
- N07751
- Family
- Age-hardenable nickel
Chemical composition
Chemical composition
Typical compositionTypical composition of the principal alloying elements; not a complete acceptance analysis.
| Element | Content (% by mass) |
|---|---|
| NiNickel | 72 |
| CrChromium | 16 |
| FeIron | 7 |
| TiTitanium | 2.3 |
| AlAluminium | 1.2 |
| NbNiobium | 0.95 |
Values describe the grade, not the analysis of a specific batch. The applicable product specification and material certificate determine acceptance. A dash does not mean zero.
The main application of 751
An exhaust valve repeatedly opens and closes while exposed to hot combustion gases. This combines heat resistance with mechanical strength. Alloy 751 is associated particularly with these engine components rather than an unspecified general high-temperature role.
Strength developed through ageing
Titanium, aluminium and niobium allow fine strengthening particles to form within 751. This ageing response supports mechanically loaded hot components as well as resistance to surface oxidation.
Properties in hot gases
Engine gases interact with a metal surface as well as heating it. Nickel and chromium contribute to 751’s resistance in this environment. Exhaust valves need both surface resistance and load-bearing ability, which together explain the alloy’s role.
Relationship between 751 and X-750
751 is closely related to X-750 but remains a separate grade. Its strong association with exhaust valves is an important application distinction. This page identifies it as 2.4694 and N07751 rather than merging the two names.
Typical application areas
Internal-combustion engine exhaust valves and hot engine components.
Product and cutting options
Relevant product forms for this material are listed below. Availability varies with grade and dimensions.