Nickel 201 UNS N02201: Properties and Applications

# Nickel 201 UNS N02201: Properties and Applications

## Introduction to Nickel 201

Nickel 201, also known by its UNS designation N02201, is a commercially pure wrought nickel 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 Nickel 201 is carefully controlled to ensure optimal performance:

– Nickel (Ni): ≥ 99.0%
– Iron (Fe): ≤ 0.40%
– Manganese (Mn): ≤ 0.35%
– Copper (Cu): ≤ 0.25%
– Carbon (C): ≤ 0.02%
– Silicon (Si): ≤ 0.35%
– Sulfur (S): ≤ 0.01%

## Physical Properties

Nickel 201 exhibits several notable physical properties:

– Density: 8.89 g/cm³ (0.321 lb/in³)
– Melting Point: 1435-1446°C (2615-2635°F)
– Electrical Resistivity: 9.5 μΩ·cm 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 201 make it suitable for various demanding applications:

– Tensile Strength: 380-550 MPa (55-80 ksi)
– Yield Strength: 100-350 MPa (15-51 ksi)
– Elongation: 40-50%
– Hardness: 45-90 HRB

## Corrosion Resistance

One of the most significant advantages of Nickel 201 is its exceptional corrosion resistance:

– Excellent resistance to reducing environments
– Good resistance to caustic alkalis
– Performs well in neutral and mildly oxidizing solutions
– Resistant to various organic acids
– Maintains performance in high-temperature environments

## Applications of Nickel 201

Due to its unique properties, Nickel 201 finds applications in numerous industries:

### Chemical Processing

– Equipment for handling caustic soda
– Reactor vessels
– Heat exchangers
– Piping systems

### Food Processing

– Equipment for fatty acid production
– Food handling machinery
– Processing vessels

### Electrical and Electronic

– Battery components
– Electronic parts
– Lead wires

### Aerospace

– Rocket engine components
– High-temperature fasteners
– Turbine components

## Fabrication and Welding

Nickel 201 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 GTAW, GMAW, and SMAW methods
– Post-weld heat treatment is generally not required

## Advantages Over Other Nickel Alloys

Nickel 201 offers several advantages compared to other nickel alloys:

– Lower carbon content than Nickel 200 (better for high-temperature applications)
– Excellent formability and weldability
– Superior thermal and electrical conductivity
– Good strength at elevated temperatures
– Excellent resistance to stress-corrosion cracking

## Conclusion

Nickel 201 UNS N02201 is a versatile material that combines excellent corrosion resistance with good mechanical properties. Its purity and performance characteristics make it suitable for demanding applications across various industries, particularly where resistance to caustic environments and high temperatures is required.