Nickel 200 Alloy Properties and Applications

# Nickel 200 Alloy Properties and Applications

## Introduction to Nickel 200 Alloy

Nickel 200, also known as UNS N02200, is a commercially pure wrought nickel alloy. It is one of the most widely used nickel alloys due to its excellent mechanical properties, corrosion resistance, and thermal conductivity. This alloy is particularly valuable in applications where high purity and resistance to corrosive environments are required.

## Chemical Composition of Nickel 200

The chemical composition of Nickel 200 alloy is as follows:

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

## Physical Properties of Nickel 200

Nickel 200 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·°C (20-100°C)

## Mechanical Properties of Nickel 200

The mechanical properties of Nickel 200 alloy vary depending on the temper and processing:

### Annealed Condition

– Tensile Strength: 380-550 MPa (55-80 ksi)
– Yield Strength (0.2% offset): 100-275 MPa (15-40 ksi)
– Elongation: 40-50%
– Hardness: 50-90 HRB

### Cold Worked Condition

– Tensile Strength: Up to 760 MPa (110 ksi)
– Yield Strength (0.2% offset): Up to 690 MPa (100 ksi)
– Elongation: 2-25%
– Hardness: Up to 100 HRB

## Corrosion Resistance

Nickel 200 offers excellent corrosion resistance in various environments:

– Resistant to neutral and alkaline salt solutions
– Performs well in reducing environments
– Excellent resistance to caustic alkalis
– Good resistance to hydrochloric and sulfuric acids at moderate temperatures and concentrations
– Resistant to dry gases like chlorine and hydrogen chloride at room temperature

## Applications of Nickel 200 Alloy

Due to its unique combination of properties, Nickel 200 finds applications in numerous industries:

### Chemical Processing

– Equipment for handling caustic soda
– Reaction vessels for organic chemical production
– Piping systems for corrosive fluids

### Food Processing

– Equipment for fatty acid production
– Food handling machinery
– Storage tanks for food-grade materials

### Electrical and Electronic

– Battery components
– Electronic tube components
– Spark plug electrodes

### Aerospace

– Rocket engine components
– Aircraft turbine blades (in certain applications)
– Spacecraft structural components

### Other Applications

– Marine engineering components
– Heat exchangers
– Desalination plants
– Nuclear reactors (certain components)

## Fabrication and Welding

Nickel 200 can be readily fabricated using standard techniques:

– Machining: Requires sharp tools and positive feeds
– Forming: Can be cold worked but requires annealing between severe operations
– Welding: Can be welded using gas tungsten arc welding (GTAW) and gas metal arc welding (GMAW) processes
– Heat Treatment: Typically annealed at 705-925°C (1300-1700°F)

## Comparison with Nickel 201 (UNS N02201)

Nickel 201 is a low-carbon version of Nickel 200, with