# Alloy HR160 UNS N12160: Properties and Applications

## Introduction to Alloy HR160 UNS N12160

Alloy HR160, also known as UNS N12160, is a nickel-chromium-cobalt alloy designed for high-temperature applications. This advanced material offers exceptional resistance to oxidation, carburization, and sulfidation in extreme environments. Developed to meet the demanding requirements of industrial processes, HR160 has become a preferred choice for engineers working with high-temperature equipment.

## Chemical Composition

The unique properties of Alloy HR160 stem from its carefully balanced chemical composition:
– Nickel (Ni): 37%
– Chromium (Cr): 28%
– Cobalt (Co): 29%
– Silicon (Si): 2.5%
– Other elements (including titanium and tungsten): Balance

This specific combination of elements creates a material with outstanding high-temperature strength and corrosion resistance.

## Mechanical Properties

Alloy HR160 exhibits remarkable mechanical properties that make it suitable for severe service conditions:

– Tensile Strength: 760 MPa (110 ksi) at room temperature
– Yield Strength: 345 MPa (50 ksi) at room temperature
– Elongation: 30% in 50 mm
– Hardness: 200 HB (Brinell)
– Creep Strength: Excellent resistance to creep deformation at temperatures up to 1150°C (2100°F)

## Key Characteristics

Several distinctive features make Alloy HR160 stand out among high-temperature alloys:

### Oxidation Resistance

The high chromium content provides exceptional oxidation resistance at temperatures up to 1200°C (2200°F). This makes HR160 particularly suitable for applications involving exposure to hot gases and combustion products.

### Carburization Resistance

HR160 demonstrates superior resistance to carburization compared to many other nickel-based alloys. This property is crucial in petrochemical processing environments where carbonaceous gases are present.

### Sulfidation Resistance

The alloy maintains good resistance to sulfidation, making it appropriate for use in sulfur-containing atmospheres found in various industrial processes.

### Thermal Stability

HR160 retains its mechanical properties after prolonged exposure to high temperatures, showing minimal microstructural changes that could degrade performance.

## Industrial Applications

Alloy HR160 finds application in numerous demanding industrial sectors:

### Petrochemical Industry

– Furnace components
– Reformer tubes
– Catalyst support grids
– Heat exchanger tubing

### Power Generation

– Gas turbine components
– Combustion system parts
– Heat recovery systems

### Industrial Furnaces

– Radiant tubes
– Retorts
– Burner nozzles
– Heat treatment fixtures

### Chemical Processing

– Reactor vessels
– Piping systems
– Heat exchangers in corrosive environments

## Fabrication and Welding

While Alloy HR160 can be fabricated using standard techniques, some special considerations apply:

### Forming

The alloy can be hot or cold formed, though hot working is generally preferred for complex shapes. Annealing may be required between forming operations to restore ductility.

### Machining

HR160 machines similarly to other nickel-based alloys but requires rigid setups, sharp tools, and appropriate cutting parameters to achieve good results.

### Welding

The alloy is readily weldable using conventional techniques such as:
– Gas tungsten arc welding (GTAW)
– Gas metal arc welding (GMAW)
– Shielded metal arc welding (SMAW)

Post-weld heat treatment is often recommended to optimize properties in the weld zone.

## Comparison with Other High-Temperature Alloys

Alloy HR160 offers several advantages over similar materials:

– Better oxidation resistance than many nickel-chromium alloys

– Superior carburization resistance compared to Alloy 800H
– Higher strength at elevated temperatures than Alloy 617
– More cost-effective than some cobalt-based superalloys for certain applications

## Maintenance and Service Life

Proper maintenance can significantly extend the service life of HR160