Alloy 25 (UNS R30605): Properties and Applications in High-Temperature Environments
# Alloy 25 (UNS R30605): Properties and Applications in High-Temperature Environments
Introduction to Alloy 25
Alloy 25, also known by its UNS designation R30605, is a nickel-chromium-iron alloy that exhibits exceptional resistance to oxidation and corrosion at elevated temperatures. This superalloy is particularly valued for its ability to maintain structural integrity in extreme environments, making it a preferred material for demanding industrial applications.
Chemical Composition
The unique properties of Alloy 25 stem from its carefully balanced chemical composition:
- Nickel (Ni): 45-50%
- Chromium (Cr): 20-23%
- Iron (Fe): Balance
- Manganese (Mn): ≤1.0%
- Silicon (Si): ≤0.5%
- Carbon (C): ≤0.1%
- Aluminum (Al): ≤0.2%
- Titanium (Ti): ≤0.2%
Key Properties
High-Temperature Performance
Alloy 25 maintains excellent mechanical strength and oxidation resistance at temperatures up to 2200°F (1200°C). Its chromium content forms a protective oxide layer that prevents further degradation at elevated temperatures.
Corrosion Resistance
The alloy demonstrates remarkable resistance to various corrosive environments, including:
- Sulfur-bearing atmospheres
- Carburizing environments
- Oxidizing and reducing conditions
- Nitriding atmospheres
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength | 75-100 ksi (517-689 MPa) |
| Yield Strength | 30-60 ksi (207-414 MPa) |
| Elongation | 30-50% |
| Hardness | RB 65-90 |
Applications in High-Temperature Environments
Alloy 25 finds extensive use in industries where materials must withstand extreme thermal and corrosive conditions:
Industrial Heating
The alloy is commonly used for:
- Furnace components
- Heat treatment fixtures
- Radiant tubes
- Combustion chambers
Chemical Processing
Alloy 25 serves in:
- Catalyst support grids
- Reaction vessels
- Heat exchangers
- Pyrolysis equipment
Power Generation
Applications include:
- Gas turbine components
- Heat recovery systems
- Boiler parts
- Exhaust systems