Nov 16 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Hot Working
Cold Working
Annealing
Hardening
Applications
Introduction
Super alloys are also known as high performance alloys. They have good creep and oxidation resistance, and are formed in different shapes. They can be strengthened by solid-solution hardening, work hardening, and precipitation hardening. They are classified into three groups such as cobalt-based, nickel-based, and iron-based alloys. They have the ability to function under high temperatures and severe mechanical stress, and also where high surface stability is required.
Inconel 706™ is a nickel-chromium-iron precipitation-hardening alloy. The following datasheet gives an overview of Inconel 706™.
Chemical Composition
The following table shows the chemical composition of Inconel 706™.
|
Elements |
Content (%) |
|
Nickel, Ni |
39-44 |
|
Iron, Fe |
38 |
|
Chromium, Cr |
14.5-17.5 |
|
Niobium, Nb |
2.50-3.30 |
|
Cobalt, Co |
≤ 1 |
|
Titanium, Ti |
≤ 0.40 |
|
Copper, Cu |
≤ 0.35 |
|
Manganese, Mn |
≤ 0.35 |
|
Silicon, Si |
≤ 0.35 |
|
Carbon, C |
≤ 0.30 |
|
Aluminum, Al |
≤ 0.060 |
|
Phosphorous, P |
≤ 0.020 |
|
Sulfur, S |
≤ 0.015 |
|
Boron, B |
≤ 0.0060 |
Physical Properties
The physical properties of Inconel 706™ are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
8.05 g/cm³ |
0.291 lb/in³ |
|
Melting point |
1360°C |
2480°F |
Mechanical Properties
The mechanical properties of Inconel 706™ are given in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
757 MPa |
109800 psi |
|
Yield strength (at strain 0.200%) |
383 MPa |
55500 psi |
|
Poisson’s ratio (precipitation hardened, calculated by mfr) |
0.382 |
0.382 |
|
Modulus of elasticity (precipitation hardened, dynamic method) |
210 GPa |
30500 ksi |
|
Elongation at break |
47% |
47% |
Thermal Properties
The thermal properties of Inconel 706™ are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (at 24-100°C/75.2-212°F) |
13.46 µm/m°C |
7.478 µin/in°F |
|
Thermal conductivity |
12.5 W/mK |
86.8 BTU in/hr.ft².°F |
Other Designations
Other designations that are equivalent to Inconel 706™ include:
-
AMS 5605
-
AMS 5606
-
AMS 5701
-
AMS 5702
-
AMS 5703
Fabrication and Heat Treatment
Machinability
Inconel 706™ can be machined using conventional machining methods which are used for iron-based alloys. Machining operations are performed using commercial coolants. High speed operations such as grinding, milling, or turning are performed using water-based coolants.
Forming
Inconel 706™ can be formed using all conventional techniques.
Welding
Inconel 706™ is welded using gas-tungsten arc welding, shielded metal-arc welding, submerged-arc welding, and gas metal-arc welding methods.
Heat Treatment
Inconel 706™ is heat treated by annealing at 927 to 1010°C (1700 to 1850°F) followed by cooling.
Forging
Inconel 706™ is forged at 983 to 1149°C (1800 to 2100°F).
Hot Working
Inconel 706™ is hot worked at 872 to 1149°C (1600 to 2100°F).
Cold Working
Inconel 706™ is cold worked using standard tooling.
Annealing
Inconel 706™ is annealed at 927 to 1010°C (1700 to 1850°F) followed by cooling.
Hardening
Inconel 706™ is hardened by heat treatment.
Applications
Inconel 706™ is mainly used in gas turbines for shafts, cases, turbine discs, and fasteners.