Hangbo Alloy Group
Shanghai · Est. 2012
N09907 technical guide: nominal chemical composition, mechanical and physical properties, corrosion resistance, welding, product forms and ASTM standards...
Incoloy 907 (UNS N09907) is a precipitation-hardenable low-expansion ni-fe-co-cr alloy. Low-expansion 900-series superalloy. High strength + steel-like thermal growth. This guide covers its nominal chemical composition, typical mechanical and physical properties, corrosion behaviour, welding, common applications, available product forms and the ASTM standards that apply — everything a specifier needs to evaluate Incoloy 907 for a project.
Incoloy 907 belongs to the precipitation-hardenable low-expansion ni-fe-co-cr alloy class of materials. It is low-expansion 900-series superalloy. It is high strength + steel-like thermal growth. It is chromium for moderate oxidation resistance.
Nominal (wt%) composition of Incoloy 907 (UNS N09907):
| Element | Composition (wt%) |
|---|---|
| Nickel (Ni) | 35.0 – 40.0 |
| Iron (Fe) | Balance |
| Cobalt (Co) | 12.0 – 16.0 |
| Chromium (Cr) | 11.0 – 14.0 |
| Niobium (Nb) | 4.0 – 5.0 |
| Titanium (Ti) | 2.5 – 3.0 |
| Aluminium (Al) | 0.2 – 0.5 |
| Carbon (C) | ≤ 0.06 |
| Manganese (Mn) | ≤ 1.0 |
| Silicon (Si) | ≤ 0.35 |
| Sulphur (S) | ≤ 0.015 |
| Phosphorus (P) | ≤ 0.015 |
Typical physical properties:
| Property | Value |
|---|---|
| Density | 8.25 g/cm³ |
| Melting Range | 1300 – 1360 °C |
| Thermal Expansion (20–600 °C) | ≈ 8.0 µm/m·K |
| Thermal Conductivity (100 °C) | 11.0 W/m·K |
| Modulus of Elasticity | 200 GPa |
Typical room-temperature mechanical properties (annealed / specified condition unless noted):
| Property | Typical Value |
|---|---|
| Tensile Strength (Rm), aged | 1170 MPa (170 ksi) |
| Yield Strength, 0.2% (Rp0.2), aged | 760 MPa (110 ksi) |
| Elongation in 50 mm, aged | 15% |
| Hardness (Rockwell C), aged | 32 – 42 HRC |
| Property | Value |
|---|---|
| Coefficient of thermal expansion | ≈ 8.0 µm/m·K (low) |
| Service temperature | Up to 600 °C |
907 is a low-expansion, precipitation-hardenable Ni-Fe-Co-Cr alloy (the 900-series) giving high strength with a thermal expansion close to steel. Chromium provides moderate oxidation resistance; the low expansion is the key property for matched casings and rings.
Welded with matching fillers under a qualified procedure including solution treat and age; aluminium/titanium require controlled heat input. Often used in the overaged condition for dimensional stability.
The grade is supplied to the following common specifications:
| Standard | Product Form / Scope |
|---|---|
| ASTM B638 | Precipitation-hardenable Ni-Fe-Cr-Co alloy bar/forgings |
| AMS 5891 | Aerospace grade |
Standards & References. Specifications cited on this page; confirm current revisions with the issuing body.
General references: Nickel Institute · AMPP (corrosion) · SAE International · ASTM International
907 is a precipitation-hardenable, low-expansion Ni-Fe-Co-Cr alloy in the 900 series. It gives high strength (≈ 1170 MPa tensile aged) with a thermal expansion near that of steel, so it is used for engine casings and rings that must stay matched to steel housings.
Aged: ≈ 1170 MPa tensile, ≈ 760 MPa yield, ≈ 15 % elongation, 32–42 HRC, with thermal expansion to 600 °C around 8.0 µm/m·K.
Both are 900-series low-expansion alloys; 909 has tighter silicon control for improved weldability and lower magnetic permeability, while 907 is the broader general grade. Properties are very similar.
Yes, with matching fillers and a solution-treat + age cycle. It is often used in the overaged condition for maximum dimensional stability.
Aero-engine casings, rings, shafts, turbine cases and high-strength fasteners where controlled thermal expansion is critical.
Bar/forgings ASTM B638, aerospace grade AMS 5891.
As a dedicated nickel alloy manufacturer serving aerospace, power generation sectors, Hangbo Alloy Group supplies the grades discussed here across all standard product forms with full ASTM/ASME documentation and EN 10204 3.1 certification. Our material is specified for applications where corrosion resistance, high-temperature strength, and traceable quality are non-negotiable. See our production & testing facilities for more on how every heat is verified.