# Alloy HR160 UNS N12160: High-Temperature Corrosion-Resistant Nickel Alloy
## Introduction to Alloy HR160
Alloy HR160, also known by its UNS designation N12160, is a high-performance nickel-based alloy specifically designed for extreme high-temperature environments. This advanced material combines excellent resistance to oxidation, carburization, and sulfidation, making it a top choice for demanding industrial applications.
## Chemical Composition
The unique properties of Alloy HR160 stem from its carefully balanced chemical composition:
– Nickel (Ni): 35-40%
– Chromium (Cr): 28-31%
– Iron (Fe): Balance
– Silicon (Si): 2.4-3.0%
– Carbon (C): 0.05-0.15%
– Rare earth elements: Small additions
This composition creates a protective oxide scale that remains stable even at elevated temperatures.
## Key Properties and Characteristics
Alloy HR160 offers several exceptional properties that make it stand out among high-temperature alloys:
### Oxidation Resistance
The alloy forms a protective chromium oxide (Cr2O3) scale that prevents further oxidation at temperatures up to 2200°F (1204°C). This scale remains adherent even during thermal cycling.
### Carburization Resistance
In carburizing environments, HR160 demonstrates superior resistance compared to standard stainless steels and many nickel alloys. The high silicon content plays a crucial role in this resistance.
### Sulfidation Resistance
The alloy performs exceptionally well in sulfur-bearing atmospheres, making it suitable for petrochemical applications where sulfur is present.
### Mechanical Properties
At room temperature:
– Tensile strength: 85-100 ksi (586-689 MPa)
– Yield strength: 35-45 ksi (241-310 MPa)
– Elongation: 30-40%
At elevated temperatures (1200°F/649°C):
– Retains approximately 70% of its room temperature strength
## Manufacturing and Fabrication
Keyword: Alloy HR160 UNS N12160
Alloy HR160 can be fabricated using standard techniques, though some considerations apply:
### Forming
The alloy can be cold worked, but intermediate annealing may be required for severe forming operations due to its work hardening characteristics.
### Welding
HR160 is readily weldable using:
– Gas tungsten arc welding (GTAW)
– Gas metal arc welding (GMAW)
– Shielded metal arc welding (SMAW)
Post-weld heat treatment is generally not required for thin sections.
### Machining
The alloy machines similarly to other austenitic materials but requires rigid setups, positive feeds, and sharp tools. Carbide tooling is recommended.
## Applications of Alloy HR160
Due to its exceptional high-temperature properties, HR160 finds use in numerous demanding applications:
### Petrochemical Industry
– Ethylene pyrolysis furnace components
– Reformer tubes
– Transfer lines in refining operations
### Power Generation
– Boiler components
– Superheater tubes
– Heat recovery systems
### Industrial Heating
– Heat treatment furnace components
– Radiant tubes
– Retorts and muffles
### Other Applications
– Chemical processing equipment
– Waste incineration systems
– Glass manufacturing equipment
## Comparison with Other High-Temperature Alloys
When compared to similar alloys, HR160 offers distinct advantages:
### Versus 304/310 Stainless Steels
– Superior oxidation resistance above 1800°F (982°C)
– Better resistance to carburization and sulfidation
– Higher creep strength at elevated temperatures
### Versus Alloy 800H
– Improved resistance to metal dusting
– Better performance in cyclic oxidation conditions
– Enhanced high-temperature strength
### Versus Alloy 617
– More cost-effective for many applications
– Better weldability in thin sections
– Superior resistance to certain types of corrosion
## Maintenance and Service Life Considerations
Proper handling and maintenance can significantly extend the service life of HR160