Jul 30 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Forging
Welding
Annealing
Cold Working
Aging
Applications
Introduction
Super alloy Altemp 286 is an iron-based alloy that can be used for both high and low temperature applications. For example it can be used for applications requiring high strength and corrosion resistance up to 704°C (1299°F) and for lower stress applications at high temperatures.
It can be applied in low temperature applications that require a ductile, non-magnetic high strength material at temperatures ranging from above room temperature down to -196°C (321°F).
Altemp 286 is a versatile material that can also be used for medium corrosion applications in aqueous solutions. This super alloy can be produced by AOD refining or vacuum induction melting.
The following sections will discuss super alloy Altemp 286 in further detail.
Chemical Composition
The chemical composition of Altemp 286 is outlined in the following table.
|
Element |
Content (%) |
|
Iron, Fe |
56 |
|
Nickel, Ni |
25 |
|
Chromium, Cr |
14.5 |
|
Molybdenum, Mo |
1.25 |
|
Titanium, Ti |
2.1 |
|
Vanadium, V |
0.3 |
|
Manganese, Mn |
0.2 |
|
Silicon, Si |
0.2 |
|
Aluminum, Al |
0.15 |
|
Carbon, C |
0.04 |
|
Phosphorus, P |
0.015 |
|
Sulfur, S |
0.0020 |
|
Boron, B |
0.006 |
Physical Properties
The physical properties of Altemp 286 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
7.92 g/cm3 |
0.286 lb/in3 |
|
Melting point |
1370-1430°C |
2500-2610°F |
Mechanical Properties
The following table shows mechanical properties of Altemp 286.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
620 MPa |
89900 psi |
|
Yield strength |
275 MPA |
39900 ksi |
|
Poisson’s ratio |
0.3 |
0.3 |
|
Elastic modulus |
201 GPa |
29200 ksi |
|
Elongation at break |
40% |
40% |
|
Hardness, Rockwell B |
85 |
85 |
Thermal Properties
The thermal properties of Altemp 286 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (at 20-100°C/68-212°F) |
16.5 µm/m°C |
9.17 µin/in°F |
|
Thermal conductivity |
15.1 W/mK |
105 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to Altemp 286 are tabulated below:
|
AISI 662 |
AMS 5525 |
AMS 5731 |
AMS 5732 |
|
AISI 660 |
AMS 5726 |
AMS 5734 |
AMS 5737 |
|
AMS 5853 |
AMS 5858 |
AMS 5895 |
DIN 1.4943 |
|
ASTM A453 Grade 660 |
ASTM A638 Grade 660 |
GE B50T1181 |
GE B50T12 |
|
SPS M250 |
AMS 5804 |
AMS 5805 |
DIN 1.4944 |
|
GE B50T81 |
|
|
|
Fabrication and Heat Treatment
Machinability
Altemp 286 can be machined using all the traditional processes. Turning, drilling, and milling can be performed on this alloy.
Forming
Altemp 286 is readily formable.
Forging
Light forging can be performed at 871-1010°C (1600-1850°F), while heavy forging can be performed at 1010-1204°C (1850-2200°F).
Welding
Welding processes of Altemp 286 is the same as that followed for stainless steel. This alloy does not require preheating or post-welding heat treatment.
Annealing
Annealing can be performed at 790°C (1450°F), followed by air cooling. Altemp 286 can be solution annealed at 982°C (1800°F) and oil quenched, which should be followed by holding at 718°C (1325°F) for 16 h and then air cooled. This heat treatment helps to strengthen the alloy.
Cold Working
Altemp 286 can be cold worked in the same manner as austenitic 300 series stainless steels.
Aging
Aging of Altemp 286 can be performed at 718°C (1325°F) for 16 h followed by air cooling. It is recommended that aging be performed after a solution heat treatment at 982°C (1800°F).
Applications
Altemp 286 can be used at 815°C (1500°F) for continuous service in oxidizing environments.
Altemp 286 can be used in the manufacture of the following:
-
Gas turbine forgings
-
Jet engine nacelles, parts, and fasteners.