Dec 20 2012
Topics Covered
IntroductionChemical CompositionPhysical PropertiesFabrication and Heat Treatment Machinability Forming Welding Cold Working Annealing HardeningApplications
Introduction
Super alloys are metallic alloys that function at high temperature environment where high surface stability and deformation resistance are mainly required. Three major classifications of super alloys include iron-base, nickel-base and cobalt-base alloys. Based on its application and composition, nickel-base and cobalt-base super alloys may be cast or wrought. The iron-base super alloys are generally wrought alloys having stainless steel technology. Super alloys are commonly forged, rolled to sheet or produced in various shapes. However, highly alloyed compositions are produced as castings. These alloys contain different elements in various combinations in order to achieve the desired result.
The following section provides detailed description of super alloy IN-102™, which is a nickel super alloy with high strength and ductility.
Chemical Composition
The following table shows the chemical composition of super alloy IN-102™.
| Element |
Content (%) |
| Chromium, Cr |
15 |
| Iron, Fe |
7 |
| Molybdenum, Mo |
3 |
| Niobium, Nb |
3 |
| Tungsten, W |
3 |
| Titanium, Ti |
0.5 |
| Aluminum, Al |
0.5 |
| Carbon, C |
0.06 |
| Nickel, Ni |
Balance |
Physical Properties
The physical properties of super alloy IN-102™ are given in the following table.
| Properties |
Metric |
Imperial |
| Density |
8.5 g/cm³ |
0.309 lb/in³ |
| Melting point |
1371°C |
2500°F |
Fabrication and Heat Treatment
Machinability
Super alloy IN-102™ can be machined using conventional techniques employed for iron based alloys. High speed operations like milling, grinding or turning can be performed using water-base coolants. Heavy lubricants are recommended for operations such as boring, broaching, tapping or drilling.
Forming
Super alloy IN-102™ can be formed by conventional means. For cold forming this alloy, heavy-duty lubricants can be used.
Welding
Welding of super alloy IN-102™ is performed through commonly used welding techniques such as gas tungsten arc welding, shielded metal-arc welding, metal-arc welding and submerged-arc welding. However, an alloy filler metal that suits this alloy need to be used.
Cold Working
Super alloy IN-102™ can be cold worked using standard tooling methods. As plain carbon steels has an ability to produce galling, they are not preferred for forming this alloy. Galling can be minimized with the help of soft die materials.
Annealing
Super alloy IN-102™ can be annealed at 982°C (1800°F) followed by rapid cooling of air.
Hardening
Super alloy IN-102™ can be hardened by cold working.
Applications
The following are the major applications of super alloy IN-102™:
- Industrial furnaces
- Gas turbine hot section components