Nickel Alloy UNS N02200: Properties and Applications

# Nickel Alloy UNS N02200: Properties and Applications

## Introduction to UNS N02200

Nickel Alloy UNS N02200, also known as commercially pure nickel or Nickel 200, is a wrought material with excellent mechanical properties and corrosion resistance. This alloy is widely used in various industries due to its unique combination of characteristics.

## Chemical Composition

The chemical composition of UNS N02200 includes:

– Nickel (Ni): 99.0% minimum
– Carbon (C): 0.15% maximum
– Manganese (Mn): 0.35% maximum
– Iron (Fe): 0.40% maximum
– Silicon (Si): 0.35% maximum
– Copper (Cu): 0.25% maximum

## Physical Properties

UNS N02200 exhibits several notable physical properties:

– Density: 8.89 g/cm³ (0.321 lb/in³)
– Melting Point: 1435-1446°C (2615-2635°F)
– Electrical Resistivity: 0.086 μΩ·m at 20°C
– Thermal Conductivity: 70 W/m·K at 20°C
– Coefficient of Thermal Expansion: 13.3 μm/m·K (20-100°C)

## Mechanical Properties

The mechanical properties of Nickel 200 make it suitable for various applications:

– Tensile Strength: 380-550 MPa (55-80 ksi)
– Yield Strength: 100-350 MPa (15-51 ksi)
– Elongation: 40-50% in 2 inches
– Hardness: 45-70 HRB

## Corrosion Resistance

One of the most significant advantages of UNS N02200 is its excellent corrosion resistance:

– Resistant to caustic alkalis up to 50% concentration at boiling temperatures
– Performs well in neutral and alkaline salt solutions
– Excellent resistance to hydrochloric and sulfuric acids at room temperature
– Good resistance to dry chlorine and hydrogen chloride gas

## Applications of UNS N02200

Due to its unique properties, Nickel 200 finds applications in various industries:

### Chemical Processing

– Equipment for handling caustic soda
– Reaction vessels for fatty acid production
– Components in synthetic fiber manufacturing

### Food Processing

– Equipment for food handling and processing
– Components in margarine and shortening production

– Vessels for edible oil processing

### Electrical and Electronic

– Battery components
– Electronic tube components
– Spark plug electrodes

### Aerospace

– Rocket engine components
– Turbine blades
– Heat exchanger tubes

## Fabrication and Welding

UNS N02200 can be readily fabricated using standard techniques:

– Hot working should be performed between 650-1230°C (1200-2250°F)
– Cold working requires intermediate annealing
– Welding can be performed using gas tungsten arc, gas metal arc, and shielded metal arc methods
– Post-weld heat treatment is generally not required

## Comparison with Nickel Alloy UNS N02201

While similar to UNS N02200, Nickel 201 (UNS N02201) has a lower carbon content (0.02% max) making it more suitable for high-temperature applications above 315°C (600°F) where carbide precipitation could occur.

## Conclusion

Nickel Alloy UNS N02200 offers an excellent combination of corrosion resistance, mechanical properties, and workability, making it a valuable material for numerous industrial applications. Its purity and performance characteristics ensure its continued use in demanding environments where other materials might fail.