Nov 15 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Other Designations
Fabrication and Heat Treatment
Machinability
Forming
Welding
Heat Treatment
Forging
Hot Working
Cold Working
Annealing
Aging
Hardening
Applications
Introduction
Super alloys or high performance alloys consist of a number of elements in a variety of combinations to achieve the desired result. They have good creep and oxidation resistance. They can be used at very high temperatures, in severe mechanical stress environments, and also where high surface stability is required. There are three groups of alloys, namely cobalt-based, nickel-based, and iron-based alloys.
Hastelloy® S is a wrought nickel base alloy. It has good ductility and strength. The following datasheet gives an overview of Hastelloy® S.
Chemical Composition
The chemical composition of Hastelloy® S is outlined in the following table.
|
Elements |
Content (%) |
|
Nickel, Ni |
67 |
|
Chromium, Cr |
14.5 - 17 |
|
Molybdenum, Mo |
14 - 16.5 |
|
Iron, Fe |
3 |
|
Cobalt, Co |
2 |
|
Tungsten, W |
1 |
|
Copper, Cu |
0.35 |
|
Manganese, Mn |
0.30 - 1.0 |
|
Silicon, Si |
0.20 - 0.75 |
|
Aluminum, Al |
0.10 - 0.50 |
|
Carbon, C |
0.020 |
|
Phosphorous, P |
0.020 |
|
Boron, B |
0.015 |
|
Sulfur, S |
0.015 |
|
Lanthanum, La |
0.010 - 0.10 |
Physical Properties
The following table shows the physical properties of Hastelloy® S.
|
Properties |
Metric |
Imperial |
|
Density |
8.75 g/cm³ |
0.316 lb/in³ |
|
Melting point |
1360°C |
2480°F |
Mechanical Properties
The mechanical properties of Hastelloy® S are given in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength (@ 1093°C/1999°F, thickness 1.10-1.60 mm/0.0433-0.0630 in.) |
110 MPa |
16000 psi |
|
Yield strength (@ 1093°C/1999°F, thickness 1.10-1.60 mm/0.0433-0.0630 in., 0.2% offset) |
52 MPa |
7540 psi |
|
Elastic modulus |
212 GPa |
30700 ksi |
|
Elongation at break (@ 982°C/1800°F, thickness 1.10-1.60 mm/0.0433-0.0630 in., in 50.8 mm) |
46% |
46% |
|
Charpy Impact (V Notch; solution heat-treated, not aged) |
190 J |
140 ft-lb |
Thermal Properties
The thermal properties of Hastelloy® S are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@ 20-93°C/68- 99°F) |
11.5 µm/m°C |
6.39 µin/in°F |
|
Thermal conductivity (@ 200°C/392°F) |
14.0 W/mK |
97.2 BTU.in/hr.ft².°F |
Other Designations
Other designations that are equivalent to Hastelloy® S include:
-
AMS 5711
-
AMS 5838
-
AMS 5873
Fabrication and Heat Treatment
Machinability
Hastelloy® S has good machining characteristics. Tooling is required to avoid work hardening and chatter.
Forming
Hastelloy® S can be formed using conventional methods.
Welding
Hastelloy® S is welded using metal inert gas and tungsten inert gas welding methods.
Heat Treatment
Hastelloy® S is heat treated by annealing at 1066°C (1950°F) followed by cooling in air.
Forging
Hastelloy® S is forged at 872 to 1149°C (1600 to 2100°F).
Hot Working
Hastelloy® S can be hot worked at 872 to 1149°C (1600 to 2100°F).
Cold Working
Hastelloy® S can be easily cold worked.
Annealing
Hastelloy® S is annealed at 1066°C (1950°F) followed by cooling in air.
Aging
Hastelloy® S is aged at 538 to 872°C (1000 to 1600°F) in order to restores its ductility and strength.
Hardening
Hastelloy® S can be hardened by cold working.
Applications
Hastelloy® S is used in gas turbines.