Jul 25 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Hot Working
Cold Working
Annealing
Applications
Introduction
Pyromet CTX-3 alloy is a high strength, precipitation hardenable superalloy that exhibits low thermal expansion coefficient over a broad temperature range. It also possesses good thermal fatigue resistance and notched stress-rupture strength over Pyromet CTX-1 alloy. The alloy is weldable, and remains unaffected by stress orientation.
The following section will provide an overview of Pyromet CTX-3 alloy.
Chemical Composition
The chemical composition of Pyromet CTX-3 alloy is outlined in the following table.
|
Element |
Content (%) |
|
Nickel, Ni |
35 - 40 |
|
Cobalt, Co |
12-16 |
|
Niobium, Nb |
4.3-5.2 |
|
Titanium, Ti |
1.2-1.8 |
|
Manganese, Mn |
1 |
|
Chromium, Cr |
1 |
|
Copper, Cu |
0.5 |
|
Silicon, Si |
0.35 |
|
Aluminum, Al |
0.2 |
|
Carbon, C |
0.06 |
|
Sulfur, S |
0.015 |
|
Boron, B |
0.012 |
|
Iron, Fe |
Balance |
Physical Properties
The following table shows the physical properties of Pyromet CTX-3 alloy.
|
Properties |
Metric |
Imperial |
|
Density |
8.28 g/cm3 |
0.299 lb/in3 |
|
Melting point |
1385°C |
2525°F |
Mechanical Properties
The mechanical properties of Pyromet CTX-3 alloy are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1180 MPa |
171000 psi |
|
Yield strength |
830 MPa |
120000 psi |
|
Elongation at break |
14% |
14% |
Thermal Properties
The thermal properties of Pyromet CTX-3 alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@25-416°C/77-781°F) |
7.50 µm/m°C |
4.17 µin/in°F |
Fabrication and Heat Treatment
Machinability
Pyromet CTX-3 alloy can be machined using conventional techniques used for iron-based alloys.
Forming
The alloy has good formability, and can be formed using all conventional methods.
Welding
Pyromet CTX-3 alloy can be welded using common welding methods such as gas-tungsten arc welding, shielded metal arc welding and submerged arc welding.
Heat Treatment
Pyromet CTX-3 alloy can be solution annealed at 982°C (1800°F) and air cooled.
Forging
Forging is carried out in the temperature range of 927 to 1149°C (1700 to 2100°F).
Hot Working
Hot working of Pyromet CTX-3 alloy is carried out at 899 to1149°C (1650 to 2100°F).
Cold Working
The alloy is cold formed using standard tooling.
Annealing
The alloy is annealed at 982°C (1800°F) and air cooled.
Applications
The following are the list of applications of Pyromet CTX-3 alloy:
-
Glass to metal sealing
-
Gas turbine seals
-
Casings
-
Other hot section structural parts.