Jul 25 2013
Topics Covered
Introduction
Chemical Composition
Physical Properties
Mechanical Properties
Thermal Properties
Fabrication and Heat Treatment
Machinability
Forming
Welding
Forging
Annealing
Hardening
Other Designations
Applications
Introduction
Nitronic 32 alloy is a nitrogen strengthened, low nickel austenitic stainless steel that is characterized by excellent fabricability and corrosion resistance, and high strength at both ambient and elevated temperatures. In addition, the alloy offers good ductility even at high strengths. Hence, the alloy serves as an ideal material for manufacturing cold-headed parts that require high mechanical properties.
The following section will provide an overview of nitronic 32 alloy.
Chemical Composition
The chemical composition of nitronic 32 alloy is outlined in the following table.
|
Element |
Content (%) |
|
Chromium, Cr |
16.5 - 19.5 |
|
Manganese, Mn |
11-14 |
|
Silicon, Si |
1 |
|
Nickel, Ni |
0.5-2.5 |
|
Nitrogen, N |
0.2-0.45 |
|
Carbon, C |
0.15 |
|
Phosphorus, P |
0.06 |
|
Sulfur, S |
0.03 |
|
Iron, Fe |
Balance |
Physical Properties
The following table shows the physical properties of nitronic 32 alloy.
|
Properties |
Metric |
Imperial |
|
Density |
7.83 g/cm3 |
0.283 lb/in3 |
|
Melting point |
1450-1510°C |
2642-2750°F |
Mechanical Properties
The mechanical properties of nitronic 32 alloy (annealed bars) are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
690 MPa |
100000 psi |
|
Yield strength |
379 MPa |
55000 psi |
|
Elongation at break |
30% |
30% |
|
Rockwell B hardness |
92 |
92 |
Thermal Properties
The thermal properties of nitronic 32 alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@23-93°C/73-200°F) |
16.16 µm/m°C |
8.98 µin/in°F |
Fabrication and Heat Treatment
Machinability
Machining nitronic 32 alloy requires slow speeds, positive feeds and abundant resulfurized lubricant.
Forming
Nitronic 32 alloy can be formed using all common forming techniques.
Welding
Nitronic 32 alloy can be welded using all welding techniques such as gas tungsten arc, gas metal arc and submerged arc welding. Pre-heating is not required for this alloy.
Forging
Nitronic 32 alloy is forged at 1093°C (2000°F) and then heated to 1177°C (2150°F).
Annealing
Nitronic 32 alloy is annealed at 1038 to 1121°C (1900 to 2050°F) and quenched in water or air.
Hardening
The alloy can be hardened through cold working.
Other Designations
An equivalent designation to nitronic 32 alloy includes ASTM A580.
Applications
The following are the list of applications of nitronic 32 alloy:
-
Fasteners
-
Communication hardware
-
Shafting.