Dec 19 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Cold Working
Welding
Forging
Forming
Machinability
Hardening
Heat Treatment
Applications
Introduction
Super alloys or high performance alloys are of three types that include iron-based, cobalt-based and nickel-based alloys. These alloys are of different shapes and they contain good oxidation and creep resistance. Super alloys can function under high mechanical stress and high temperatures and also in places that require high surface stability. Super alloys can be strengthened by precipitation hardening, solid-solution hardening and work hardening methods.
Super alloy 49 is an alloy of iron and nickel with chemical composition controlled for magnetic properties. The following datasheet provides an overview of super alloy 49.
Chemical Composition
The chemical composition of super alloy 49 is outlined in the following table.
|
Element |
Content (%) |
|
Iron, Fe |
51 |
|
Nickel, Ni |
48 |
|
Manganese, Mn |
0.50 |
|
Silicon, Si |
0.35 |
|
Carbon, C |
0.020 |
Physical Properties
The following table shows the physical properties of super alloy 49.
|
Properties |
Metric |
Imperial |
|
Density |
8.165 g/cm³ |
0.295 lb/in³ |
|
Melting point |
1427°C |
2600°F |
Mechanical Properties
The mechanical properties of super alloy 49 are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
655 MPa |
95000 psi |
|
Yield strength |
552 MPa |
80000 psi |
|
Elastic modulus |
166 GPa |
24100 ksi |
|
Elongation at break (In 50 mm) |
25% |
25% |
|
Reduction of area |
62% |
62% |
|
Hardness, Rockwell B |
98 |
98 |
Thermal Properties
The thermal properties of super alloy 49 are given in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@25-204°C/77-400°F) |
8.28 µm/m°C |
4.60 µin/in°F |
|
Thermal conductivity |
13.0 W/mK |
90.2 BTU in/hr.ft².°F |
Other Designations
Equivalent material to super alloy 49 includes ASTM A753 ALLOY 2.
Fabrication and Heat Treatment
Cold Working
Super alloy 49 can be readily cold worked. Specification of an annealed grade is required for general forming, and specification of a deep drawing grade is required for forming operation.
Welding
Super alloy 49 can be welded by conventional welding techniques.
Forging
Super alloy 49 can be forged at 1177°C (2150°F).
Forming
Standard forming techniques can be used for super alloy 49 as it has good ductility.
Machinability
Super alloy 49 has similar machining behavior like that of the austenitic stainless steels. Usage of sulfur should be avoided in the machining process as the cutting oils present in sulfur will contaminate this alloy.
Hardening
Super alloy 49 can be hardened only by being cold worked.
Heat Treatment
Super alloy 49 can be annealed at 1177°C (2150°F) for 4 h in dry hydrogen, cooled in a furnace for 1 h at 66-427°C (150-800°F) and finally cooled in air. This alloy cannot be heat-treated for strengthening purposes. Super alloy 49 can also be strain relief annealed for ½ h at 816°C (1500°F) in inert gas and dry hydrogen.
Applications
Super alloy 49 is suitable for use in magnetic shielding, transformer cores and solenoid cores. Based on the product form and purpose of application this alloy is available in 3 grades that include:
-
Strip, Rotor Grade
-
Strip, Transformer Grade
-
Bar, wire, rod and shielding strip.