# Alloy 230 UNS R06230: Properties and Applications

## Introduction to Alloy 230

Alloy 230, also known as UNS R06230, is a nickel-chromium-tungsten-molybdenum alloy that offers exceptional high-temperature strength and oxidation resistance. This superalloy is widely used in industries where components are exposed to extreme environments, such as aerospace, power generation, and chemical processing.

## Chemical Composition

The unique properties of Alloy 230 stem from its carefully balanced chemical composition:

– Nickel (Ni): 57% (minimum)
– Chromium (Cr): 20-24%
– Tungsten (W): 13-15%
– Molybdenum (Mo): 1-3%
– Iron (Fe): ≤3%
– Cobalt (Co): ≤5%
– Carbon (C): 0.05-0.15%
– Silicon (Si): ≤0.5%
– Manganese (Mn): ≤0.5%
– Aluminum (Al): ≤0.5%
– Boron (B): ≤0.015%
– Lanthanum (La): 0.005-0.05%

## Mechanical Properties

Alloy 230 exhibits excellent mechanical properties across a wide temperature range:

– Tensile Strength: 120-150 ksi (827-1034 MPa)
– Yield Strength: 60-90 ksi (414-621 MPa)
– Elongation: 30-50%
– Hardness: 180-220 HB

## Physical Properties

The physical characteristics of Alloy 230 include:

– Density: 0.305 lb/in³ (8.44 g/cm³)
– Melting Range: 2410-2490°F (1320-1365°C)
– Thermal Conductivity: 6.5 BTU·in/(hr·ft²·°F) at 212°F (11.2 W/m·K at 100°C)
– Electrical Resistivity: 46.5 μΩ·in (118 μΩ·cm) at 70°F (21°C)

## Key Features and Advantages

Alloy 230 offers several distinct advantages:

– Excellent high-temperature strength and creep resistance
– Outstanding oxidation resistance up to 2100°F (1150°C)
– Good thermal stability and low thermal expansion
– Resistance to carburization and nitriding environments
– Superior resistance to hot corrosion and sulfidation
– Good fabricability and weldability

## Applications of Alloy 230

Due to its exceptional properties, Alloy 230 finds applications in various demanding industries:

### Aerospace Industry

– Combustion chambers
– Afterburner components
– Turbine seals and rings

### Power Generation

– Gas turbine components
– Combustion liners
– Transition ducts
– Heat exchangers

### Chemical Processing

– High-temperature reactors
– Furnace components
– Catalyst support grids
– Heat treatment fixtures

### Other Applications

– Nuclear reactors
– Heat treating equipment
– Petrochemical processing
– Waste incineration systems

## Fabrication and Welding

Alloy 230 can be readily fabricated using standard techniques:

– Hot working: 2050-2250°F (1120-1230°C)
– Cold working: Good ductility allows for moderate cold working
– Annealing: 2050-2250°F (1120-1230°C) followed by rapid cooling
– Welding: Can be welded using GTAW, GMAW, and SMAW processes

## Conclusion

Alloy 230 UNS R06230 is a versatile high-performance nickel-based superalloy that combines excellent high-temperature strength with outstanding oxidation resistance. Its unique combination of properties makes it an ideal choice for applications in extreme environments across multiple industries. The alloy’s good fabricability and weldability further enhance its appeal for