# Nickel Alloy UNS N02200: Properties and Applications

## Introduction to UNS N02200

Nickel Alloy UNS N02200, also known as commercially pure nickel, is a high-purity wrought alloy with excellent corrosion resistance and thermal conductivity. This alloy is widely used in various industries due to its unique combination of properties.

## Chemical Composition

The chemical composition of UNS N02200 is characterized by its high nickel content:

– Nickel (Ni): 99.0% min
– Carbon (C): 0.15% max
– Manganese (Mn): 0.35% max
– Iron (Fe): 0.40% max
– Silicon (Si): 0.35% max
– Copper (Cu): 0.25% max
– Sulfur (S): 0.01% max

## 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)
– Thermal Conductivity: 70 W/m·K (40.4 BTU·in/hr·ft²·°F) at 100°C
– Electrical Resistivity: 0.096 µΩ·m at 20°C
– Magnetic Permeability: <1.01 (non-magnetic when annealed)

## Mechanical Properties

The mechanical properties of UNS N02200 vary depending on the temper condition:

### Annealed Condition

– Tensile Strength: 345-485 MPa (50-70 ksi)
– Yield Strength (0.2% offset): 105-345 MPa (15-50 ksi)
– Elongation: 40-50%
– Hardness: 45-90 HRB

### Cold Worked Condition

– Tensile Strength: up to 760 MPa (110 ksi)
– Yield Strength (0.2% offset): up to 690 MPa (100 ksi)
– Elongation: 2-15%
– Hardness: up to 100 HRB

## Corrosion Resistance

UNS N02200 offers excellent corrosion resistance in various environments:

– Outstanding resistance to caustic alkalis
– Good resistance to neutral and alkaline salt solutions
– Excellent performance in reducing environments

– Resistance to organic acids and food processing environments
– Limited resistance to oxidizing acids and salt solutions

## Applications of UNS N02200

Due to its unique properties, UNS N02200 finds applications in numerous industries:

### Chemical Processing

– Caustic soda production equipment
– Chlorine handling components
– Hydrogen fluoride processing

### Food Processing

– Food handling equipment
– Margarine and shortening production
– Fatty acid processing

### Electrical and Electronic

– Battery components
– Electronic tube components
– Spark plug electrodes

### Other Applications

– Marine engineering components
– Aerospace applications
– Heat exchangers in corrosive environments
– Handling of fluorine and fluorides

## Fabrication and Welding

UNS N02200 can be readily fabricated using standard techniques:

### Forming

– Excellent cold working properties
– Can be hot worked between 650-1230°C (1200-2250°F)
– Annealing recommended after severe cold working

### Welding

– Weldable by all standard methods
– Recommended filler metal: ERNi-1
– Gas tungsten arc welding (GTAW) is preferred
– Post-weld annealing may be required for critical applications

## Heat Treatment

UNS N02200 can be heat treated to achieve desired properties:

– Annealing: 705-925°C (1300-1700°F) followed by rapid cooling
– Stress relieving: 260-425°C (500-800°F) for 1