Nov 19 2012
Topics Covered
Introduction
Chemical Composition
Physical properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Welding
Cold Working
Annealing
Hardening
Applications
Introduction
Super alloys or high performance alloys have the capacity to function at high temperatures and extreme mechanical stress, and also where high surface stability is required. They are available in different shapes, and have good creep and oxidation resistance. Solid-solution hardening, work hardening, and precipitation hardening are performed for improving strength of this alloy.
Hastelloy(r) G50(r) is a nickel-chromium-molybdenum and iron alloy. The following datasheet gives an overview of hastelloy(r) G50(r).
Chemical Composition
The chemical composition of hastelloy (r) G50(r) is outlined in the following table.
|
Elements |
Content (%) |
|
Nickel, Ni |
≥ 50 |
|
Chromium, Cr |
19-21 |
|
Iron, Fe |
15-20 |
|
Molybdenum, Mo |
8-10 |
|
Cobalt, Co |
≤ 2.50 |
|
Manganese, Mn |
≤ 1 |
|
Silicon, Si |
≤ 1 |
|
Tungsten, W |
≤ 1 |
|
Niobium, Nb |
≤ 0.50 |
|
Copper, Cu |
≤ 0.50 |
|
Aluminum, Al |
≤ 0.40 |
|
Phosphorous, P |
≤ 0.040 |
|
Carbon, C |
≤ 0.020 |
|
Sulfur, S |
≤ 0.015 |
Physical properties
The physical properties of hastelloy(r) G50(r) are given in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
8.33 g/cm³ |
0.301 lb/in³ |
|
Melting point |
1399°C |
2550°F |
Mechanical Properties
The following table shows the mechanical properties of Hastelloy(r) G50(r).
|
Properties |
Metric |
Imperial |
|
Tensile strength |
≥ 760 MPa |
≥ 110000 psi |
|
Yield strength (@ strain 0.200%) |
700-860 MPa |
102000-125000 psi |
|
Elastic modulus (room temp.) |
192 GPa |
27800 ksi |
|
Elongation at break (in 50 mm) |
≥ 20% |
≥ 20% |
|
Hardness, Brinell (estimated from Rockwell C for Brinell 10 mm ball/3000 kg load) |
290 |
290 |
|
Hardness, Knoop (estimated from Rockwell C) |
345 |
345 |
|
Hardness, Rockwell A (estimated from Rockwell C) |
66 |
66 |
|
Hardness, Rockwell C |
≤ 31 |
≤ 31 |
|
Hardness, Vickers (estimated from Rockwell C) |
300 |
300 |
Thermal Properties
The thermal properties of hastelloy(r) G50(r) are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@ 20-95°C/68- 03°F) |
13.0 µm/m°C |
7.22 µin/in°F |
Fabrication and Heat Treatment
Machinability
Hastelloy(r) G50(r) is machined using conventional methods which are used for iron-based alloys. It has machining characteristics similar to that of austenitic stainless steels.
Forming
Hastelloy(r) G50(r) can be formed using conventional methods.
Welding
Hastelloy (r) G50(r) is welded using gas tungsten arc welding, metal-arc welding, and shielded metal-arc welding methods. Submerged-arc welding method is not preferred for this alloy.
Cold Working
Hastelloy (r) G50(r) can be cold worked using standard tooling. Soft die materials such as zinc alloy and bronze are used for reducing galling problems.
Annealing
Hastelloy(r) G50(r) is annealed at 1149°C (2100°F) followed by rapidly cooling or quenching in water.
Hardening
Hastelloy(r) G50(r) is hardened by cold working.
Applications
Hastelloy(r) G50(r) is suitable for oil production applications.