Jul 5 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 made up of nickel and chromium. These alloys are characterised by their high-temperature low-creep and high performance. Additives like titanium and aluminium are used for enhancing the strength of the alloy. The NIMONIC alloy was first developed during the 1940s in England.
NIMONIC alloys that are available commercially are NIMONIC 75. NIMONIC 90, NIMONIC 100, NIMONIC 80A, 81, 86, NIMONIC 90, NIMONIC PE11 and 16. The NIMONIC alloy 75 is an 80/20 nickel-chromium alloy containing titanium and carbon as additives. This alloy was first introduced for use as turbine blades during the 1940s. It is readily fabricated and welded. This alloy exhibits good corrosion resistance, mechanical properties and heat resistance. Some of the standard forms in which this alloy is available are extruded section, hexagon flats, pipe, plate, strip and wire.
This datasheet will look into the chemical composition, properties and applications of NIMONIC alloy 75.
Chemical Composition
The chemical composition of NIMONIC alloy 75 is given in the following table.
|
Element |
Content (%) |
|
Nickel, Ni |
Remainder |
|
Chromium, Cr |
18-21 |
|
Iron, Fe |
5.00 max |
|
Silicon, Si |
1.00 max |
|
Manganese, Mn |
1.00 max |
|
Titanium, Ti |
0.2-0.6 |
|
Copper, Cu |
0.5 |
|
Carbon, C |
0.08-0.15 |
Physical Properties
The following table discusses the physical properties of NIMONIC alloy 75.
|
Properties |
Metric |
Imperial |
|
Density |
8.37 gm/cm3 |
0.302 lb/in3 |
Mechanical Properties
The mechanical properties of NIMONIC alloy 75 are tabulated below.
|
Properties |
Metric |
Imperial |
|
Tensile strength(annealed) |
750 MPa |
109 ksi |
|
Yield strength(annealed) |
275 MPa |
40 ksi |
|
Elongation at Break |
42% |
42% |
|
Modulus of Elasticity |
206 GPa |
29878 ksi |
Other Designations
Some of the other designations that are used to denote NIMONIC alloy 75 are as below:
-
UNS N06075
-
BS HR5
-
HR203
-
HR403
-
HR504
-
DIN 17742
-
DIN 17750-17752
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 75 can be welded using common techniques, using a matching filler metal. A prerequisite for welding is that the metal should be annealed. Manual metal arc welding, tungsten inert gas welding and metal inert gas welding suit the alloy.
Hot working
NIMONIC alloy 75 can be hot worked at temperature ranges of 1220-950°C (2230-1740°F).
Forging
NIMONIC alloy 75 can be hot forged at temperatures in the range of 982-1204°C (1800-2200°F).
Cold working
Cold working may be done on the alloy.
Annealing
NIMONIC alloy 75 should be annealed at 1051°C (1925°F) and air cooled.
Applications
The NIMONIC alloy 75 is used in the following applications:
-
Aerospace fasteners
-
Gas turbine engineering
-
Industrial furnace structural parts
-
Heat treatment equipments
-
Nuclear engineering.