Nov 23 2012
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Welding
Forging
Cold Working
Annealing
Aging
Applications
Introduction
Super alloys or high performance alloys contain many elements in a variety of combinations to reach a desired result. These alloys are excellent for use in environments with high temperatures and severe mechanical stress, and also in cases where high surface stability is needed. Super alloys also provide good creep and oxidation resistance.
Strengthening of super alloys is performed by work hardening, solid-solution hardening, and precipitation hardening methods.
HAYNES(r) 242 is a nickel-chromium-molybdenum alloy that is age-hardenable to gain high strength and oxidation resistance at moderately high temperatures.
The following datasheet will provide more details about HAYNES(r) 242.
Chemical Composition
The following table shows the chemical composition of HAYNES(r) 242.
|
Element |
Content (%) |
|
Nickel, Ni |
58 |
|
Molybdenum, Mo |
24-26 |
|
Chromium, Cr |
7-9 |
|
Cobalt, Co |
2.50 |
|
Iron, Fe |
2 |
|
Manganese, Mn |
0.80 |
|
Silicon, Si |
0.80 |
|
Copper, Cu |
0.50 |
|
Aluminum, Al |
0.50 |
|
Carbon, C |
0.030 |
|
Boron, B |
0.0060 |
Physical Properties
The physical properties of HAYNES(r) 242 are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
9.05 g/cm³ |
0.327 lb/in³ |
|
Melting point |
1290-1375°C |
2350-2507°F |
Mechanical Properties
The mechanical properties of annealed and aged HAYNES(r) 242 are provided below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
1290 MPa |
187000 psi |
|
Yield strength (@strain 0.200%) |
845 MPa |
123000 psi |
|
Elastic modulus |
229 GPa |
33200 ksi |
|
Elongation at break (in 4D) |
33.70% |
33.70% |
|
Reduction of area |
45.70% |
45.70% |
|
Hardness, Brinell (converted from Vickers hardness) |
257 |
257 |
|
Hardness, Knoop (converted from Vickers hardness) |
286 |
286 |
|
Hardness, Rockwell C (converted from Vickers hardness) |
19 |
19 |
|
Hardness, Vickers |
271 |
271 |
Thermal Properties
The thermal properties of HAYNES(r) 242 are given below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@20-100°C/68-212°F) |
10.8 µm/m°C |
6 µin/in°F |
|
Thermal conductivity |
11.3 W/mK |
78.4 BTU in/hr.ft².°F |
Fabrication and Heat Treatment
Machinability
Traditional machining methods used for iron-based alloys can be used for HAYNES(r) 242. During high-speed operations such as turning, grinding, or milling, it is recommended that water-based coolants are used. The use of heavy lubricants for drilling, tapping, broaching or boring is suitable. In cases where turning with a continuous cut is performed, carbide tools are suitable.
Forming
HAYNES(r) 242 can be formed using conventional methods as it has good ductility. Powerful equipment is required.
Welding
HAYNES(r) 242 is weldable using all the conventional methods. Some of the commonly used methods are metal-arc welding, gas-tungsten arc welding, shielded metal-arc welding, and submerged-arc welding. It is recommended that matching alloy filler metal should be used. Before the welding process begins, the surface to be welded should be cleaned and free from oil, paint or crayon stains.
Forging
Forging of HAYNES(r) 242 should be performed in the range of 1149-927°C (2100-1700°F) using conventional methods.
Cold Working
HAYNES(r) 242 can be cold worked using conventional tooling. To minimize galling and provide a neat finish, soft die materials containing bronze and zinc alloys are recommended. However, the life of the die is short.
Annealing
Annealing of HAYNES(r) 242 is performed at 1093°C (2000°F) and then followed by fast cooling.
Aging
Age-hardening thermal treatment can be performed on HAYNES(r) 242 in the annealed condition by heating at 649°C (1200°F) for 24 h and then followed by air cooling.
Applications
HAYNES(r) 242 is used in hot section seal rings, ducts and fasteners. The alloy is also applied in petro-chemical process equipment that is exposed to fluorine compounds or acid.