Jul 10 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 50 alloy is an austenitic, nitrogen strengthened steel that has corrosion resistance superior to grade 316 and 317 stainless steels. It has very good mechanical properties at both sub-zero and elevated temperatures. The alloy is capable of retaining low magnetic permeability even after exposure to sub-zero temperatures or severe cold working conditions.
In addition, the alloy has excellent resistance to sulfide stress cracking and intergranular attack. It can be readily fabricated, and it is considerably stronger than the conventional 300 series stainless steels.
The following datasheet will provide an overview of nitronic 50 alloy.
Chemical Composition
The chemical composition of nitronic 50 alloy is outlined in the following table.
|
Element |
Content (%) |
|
Chromium, Cr |
20.5-23.5 |
|
Nickel, Ni |
11.5-13.5 |
|
Manganese, Mn |
4-6 |
|
Molybdenum, Mo |
1.5-3 |
|
Silicon, Si |
1 |
|
Nitrogen, N |
0.2-0.4 |
|
Niobium, Nb |
0.1-0.3 |
|
Vanadium, V |
0.1-0.3 |
|
Carbon, C |
0.06 |
|
Sulfur, S |
0.03 |
|
Iron, Fe |
Balance |
Physical Properties
The following table shows the physical properties of nitronic 50 alloy.
|
Properties |
Metric |
Imperial |
|
Density |
7.89 g/cm3 |
0.285 lb/in3 |
Mechanical Properties
The mechanical properties of nitronic 50 alloy are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength at break |
≥ 689 MPa |
≥ 100000 psi |
|
Yield strength |
≥ 379 MPa |
≥ 55000 psi |
|
Elongation at break |
≥ 35% |
≥ 35% |
Thermal Properties
The thermal properties of nitronic 50 alloy are given in the following table.
|
Properties |
Metric |
Imperial |
|
Thermal expansion co-efficient (@25.6-93.3°C/78-200°F) |
16.2 µm/m°C |
9 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
Other designations that are equivalent to nitronic 50 alloy include the following:
|
ASTM A182 (XM-19) |
ASTM A269 (XM-19) |
ASTM A412 (XM-19) |
|
ASTM A193 (B8R, B8RA) |
ASTM A276 |
ASTM A479 (XM-19) |
|
ASTM A194 (B8R, B8RA) |
ASTM A312 (XM-19) |
ASTM A580 (XM-19) |
|
ASTM A240 (XM-19) |
ASTM A336 (XM-19) |
ASTM A813 (TP XM-19) |
|
ASTM A249 (XM-19) |
ASTM A403 (XM-19) |
DIN 1.3964 |
Applications
The following are the list of applications of nitronic 50 alloy:
-
Fasteners
-
Marine hardware
-
Boat shafting
-
Pumps and valves