# Alloy 330 UNS N08330: Properties and Applications
## Introduction to Alloy 330 UNS N08330
Alloy 330, also known as UNS N08330, is a nickel-iron-chromium austenitic alloy designed for high-temperature applications. This material offers excellent resistance to oxidation and carburization, making it a popular choice in various industrial sectors.
## Chemical Composition
The chemical composition of Alloy 330 plays a crucial role in its performance characteristics:
– Nickel (Ni): 34-37%
– Chromium (Cr): 17-20%
– Iron (Fe): Balance
– Silicon (Si): 0.75-1.50%
– Manganese (Mn): ≤2.00%
– Carbon (C): ≤0.08%
– Sulfur (S): ≤0.030%
– Phosphorus (P): ≤0.030%
## Mechanical Properties
Alloy 330 exhibits impressive mechanical properties across a wide temperature range:
– Tensile Strength: 75 ksi (517 MPa) min
– Yield Strength: 30 ksi (207 MPa) min
– Elongation: 30% min
– Hardness: Rb 85 max
– Density: 0.290 lb/in³ (8.03 g/cm³)
## Physical Properties
The physical characteristics of Alloy 330 include:
– Melting Range: 2500-2600°F (1371-1427°C)
– Thermal Expansion Coefficient: 8.9 µin/in-°F (20-1000°C)
– Thermal Conductivity: 12.4 Btu·in/ft²·hr·°F at 212°F (100°C)
– Electrical Resistivity: 37.5 µΩ·in at 70°F (21°C)
## Key Features and Advantages
Alloy 330 offers several notable benefits:
– Excellent resistance to oxidation up to 2100°F (1149°C)
– Good resistance to carburization and nitriding
– Superior strength at elevated temperatures
– Good resistance to thermal shock
– Excellent formability and weldability
– Resistance to sulfur-containing atmospheres
## Common Applications
Due to its unique properties, Alloy 330 finds use in numerous demanding applications:
### Industrial Furnace Components
– Radiant tubes
– Muffles
– Retorts
– Roller hearths
– Conveyor belts
### Heat Treatment Equipment
– Annealing boxes
– Basket fixtures
– Quench fixtures
– Furnace fans
### Petrochemical Industry
– Reformer tubes
– Catalyst support grids
– Heat exchanger tubing
– Pyrolysis equipment
### Other Applications
– Aircraft exhaust systems
– Nuclear reactor components
– Chemical processing equipment
– Food processing equipment
## Fabrication and Welding
Keyword: Alloy 330 UNS N08330
Alloy 330 can be readily fabricated using standard techniques:
– Machining: Requires slow speeds and heavy feeds
– Forming: Can be cold worked using standard methods
– Welding: Can be welded using GTAW, GMAW, and SMAW processes
– Post-weld heat treatment: Generally not required
## Comparison with Similar Alloys
While Alloy 330 shares some characteristics with other high-temperature alloys, it offers distinct advantages:
– Compared to 304/310 stainless steels: Better oxidation resistance and higher temperature capability
– Compared to Inconel alloys: More cost-effective for many applications
– Compared to RA330: Similar composition but with tighter controls on impurities
## Conclusion
Alloy 330 UNS N08330 remains a versatile and reliable material for high-temperature applications where oxidation resistance and strength are critical. Its balanced combination of properties makes it suitable for a wide range of industrial applications, particularly in furnace components and heat treatment equipment. The alloy’s excellent performance at elevated temperatures, coupled with good fabricability,
