Jul 4 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Welding
Hot Working
Applications
Introduction
Super alloys are high performance alloys that are known for their excellent mechanical strength and resistance to creep at elevated temperatures, good surface stability, and good corrosion and oxidation resistance.
Super alloy INCONEL MA758 is an oxide-dispersion strengthened nickel-chromium super alloy that is made by mechanical alloying. High-temperature strength is improved due to the use of yttrium oxide for dispersion strengthening.
The following section explains in detail about super alloy INCONEL MA758.
Chemical Composition
The chemical composition of INCONEL MA758 is outlined in the following table.
|
Element |
Content (%) |
|
Nickel. Ni |
67.55 |
|
Chromium, Cr |
30 |
|
Iron, Fe |
1 |
|
Yttrium oxide, Y2O3 |
0.60 |
|
Titanium, Ti |
0.5 |
|
Carbon, C |
0.050 |
|
Aluminum, Al |
0.3 |
Physical Properties
The physical properties of INCONEL MA758 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Density |
8.14 g/cm3 |
0.294 lb/in3 |
|
Melting point |
1375 °C |
2507 °F |
Mechanical Properties
The following table shows mechanical properties of INCONEL MA758 (bar) alloy.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
173 MPa |
25100 psi |
|
Yield strength |
151 MPa |
21900 psi |
|
Elongation at break |
22% |
22% |
Thermal Properties
The thermal properties of INCONEL MA758 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@0.000-100°C/32-212°F) |
12.47 µm/m°C |
6.928 µin/in°F |
Fabrication and Heat Treatment
Machinability
INCONEL MA758 is readily machined in the fully recrystallized condition and has similar machining characteristics to solution-annealed INCONEL 718. Ordinary sulfurized mineral oil can be used for this process. Water-based coolants are recommended for use in high-speed operations such as milling, turning, and grinding.
Welding
INCONEL alloy MA 758 is weldable. Mechanical fastening methods such as bolting and riveting are commonly used for joining INCONEL alloy MA 758 to itself and to other alloys.
Hot Working
INCONEL MA758 is readily fabricated and can be hot formed into variety of desired shapes for use in thermal processing applications.
Applications
INCONEL MA758 is used in the following application areas:
-
In fuel atomizer application in diesel engines
-
Components used in heat-treatment processes such as furnace skid rails, jigs, hearth rollers, and tools.