Oct 25 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
Applications
Introduction
Super alloys are also known as high performance alloys. They contain many elements in a variety of combinations designed to provide unique material properties for specific applications. These alloys can function at very high temperatures and in severe mechanical stress environments, and also where high surface stability is required. They have high creep and oxidation resistance.
Strengthening of super alloys is performed by solid-solution hardening, work hardening, and precipitation hardening methods.
HASTELLOY(r) B-2 is a wrought nickel-molybdenum alloy that can be used in the ‘as welded’ condition. This alloy has excellent resistance to all temperatures and concentrations of hydrochloric acid. Additionally, it has good stress corrosion cracking and pitting resistance as well. However, due to the presence of high molybdenum content, this alloy is expensive.
The following datasheet will provide more details about HASTELLOY(r) B-2.
Chemical Composition
The following table shows the chemical composition of HASTELLOY(r) B-2.
|
Element |
Content (%) |
|
Nickel, Ni |
69 |
|
Molybdenum, Mo |
28 |
|
Iron, Fe |
2 |
|
Chromium, Cr |
1 |
|
Cobalt, Co |
1 |
|
Manganese, Mn |
1 |
|
Silicon, Si |
0.10 |
|
Carbon, C |
0.01 |
Physical Properties
The physical properties of HASTELLOY(r) B-2 are outlined in the following table.
|
Properties |
Metric |
Imperial |
|
Density |
9.22 g/cm³ |
0.333 lb/in³ |
|
Melting point |
1427°C |
2600°F |
Mechanical Properties
The mechanical properties of HASTELLOY(r) B-2 are provided below.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
914 MPa |
133000 psi |
|
Yield strength (@strain 0.200%) |
396 MPa |
57400 psi |
|
Elastic modulus |
217 GPa |
31500 ksi |
|
Elongation at break (in 50.8 mm) |
55% |
55% |
|
Hardness, Brinell (converted from Rockwell B hardness) |
168 |
168 |
|
Hardness, Knoop (converted from Rockwell B hardness) |
186 |
186 |
|
Hardness, Rockwell B |
98 |
98 |
|
Hardness, Vickers (converted from Rockwell B hardness) |
241 |
241 |
Thermal Properties
The thermal properties of HASTELLOY(r) B-2 are given below.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@21-100°C/69.8-212°F) |
10.3 µm/m°C |
5.72 µin/in°F |
|
Thermal conductivity |
11.1 W/mK |
77 BTU in/hr.ft².°F |
Other Designations
Equivalent materials to HASTELLOY(r) B-2 are:
-
ASTM B333
-
ASTM B335
-
ASTM B366
-
ASTM B564
-
ASTM B619
-
ASTM B622
-
ASTM B626
-
DIN 2.4615
-
DIN 2.4617
-
GE B50T38
Fabrication and Heat Treatment
Machinability
HASTELLOY(r) B-2 can be machined using all the traditional machining methods.
Forming
HASTELLOY(r) B-2 can be easily formed using all the conventional methods.
Welding
HASTELLOY(r) B-2 can be welded using the traditional welding methods.
Heat Treatment
HASTELLOY(r) B-2 can be solution treated at 1065°C (1950°F) and then rapidly quenched in normal conditions that require product forms to be furnished and used. In cases where bright annealed product forms such as sheet and strip are required, HASTELLOY(r) B-2 can be solution treated at 1149°C (2100°F) and then cooled in a hydrogen atmosphere so as to avoid oxidation of the bright surface.
Forging
HASTELLOY(r) B-2 can be easily forged in the temperature range of 1232-982°C (2250-1800°F).
Hot Working
HASTELLOY(r) B-2 can be hot worked.
Cold Working
HASTELLOY(r) B-2 can be cold worked.
Applications
HASTELLOY(r) B-2 is mainly used in chemical process equipment.