Jul 4 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Other Designations
Fabrication
Machinability
Welding
Hot working
Forging
Cold working
Annealing
Applications
Introduction
NIMONIC alloys are primarily composed of nickel and chromium. These alloys are known for their high-temperature low-creep and high performance. Additives like aluminium, carbon and titanium are infused into the alloy. The NIMONIC alloy was first developed in 1940 in England. NIMONIC alloys available commercially are NIMONIC 75, NIMONIC 80A, 81, 86, NIMONIC PE11 and 16.
NIMONIC alloy 80A is a wrought, age-hardened alloy that is strengthened by additives like titanium, aluminium and carbon. It is manufactured by high-frequency melting and casting in air. It is similar to NIMONIC alloy 75. It has good corrosion and oxidation resistance. The creep rupture and tensile properties are high at 815°C (1500°F).
This datasheet will look into the chemical composition, properties and applications of NIMONIC alloy 80A.
Chemical Composition
The chemical composition of NIMONIC alloy 80A is given in the following table.
|
Element |
Content (%) |
|
Nickel, Ni |
69 |
|
Chromium, Cr |
18-21 |
|
Iron, Fe |
≤3 |
|
Cobalt, Co |
≤2 |
|
Titanium, Ti |
1.8-2.7 |
|
Aluminum, Al |
1.0-1.8 |
|
Others |
Remainder |
Physical Properties
The following table discusses the physical properties of NIMONIC alloy 80A.
|
Properties |
Metric |
Imperial |
|
Density |
8.19 gm/cm3 |
0.296 lb/in3 |
Mechanical Properties
The mechanical properties of NIMONIC alloy 80A are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength(annealed) |
1250 MPa |
181 ksi |
|
Yield strength(annealed) |
780 MPa |
113 ksi |
|
Elongation at Break |
30% |
30% |
Other Designations
Some of the other designations that are used to denote NIMONIC alloy 80A are as below:-
-
UNS N07080
-
BS 3076
-
HR1
-
HR401
-
HR601
-
HR201
-
ASTM B637
-
DIN 17742
-
DIN17754
Fabrication
Machinability
The conventional machining techniques used on iron alloys may be used for this alloy. This alloy work-hardens during machining.
Welding
NIMONIC alloy 80A can be welded using common techniques, using a matching filler metal. A prerequisite for welding is that the metal should be solution treated. Fusion welding by tungsten inert gas welding and metal inert gas welding will be suitable for this alloy.
Hot working
NIMONIC alloy 80A can be hot worked at temperature ranges of 1050-1200°C (1920-2190°F).
Forging
NIMONIC alloy 80A can be hot forged at temperatures in the range of 982-1176°C (1800-2150°F).
Cold working
Cold working may be done on the alloy.
Annealing
NIMONIC alloy 80A should be annealed at 1079°C (1975°F) for about 8 hours and air cooled.
Applications
The NIMONIC alloy 80A is used in the following applications:
-
Gas turbine engineering
-
Automobile exhaust valves
-
Die-casting inserts and cores
-
Nuclear boiler tube parts.