# Hastelloy X Alloy UNS N06002: Properties and Applications
## Introduction to Hastelloy X
Hastelloy X, also known as UNS N06002, is a nickel-chromium-iron-molybdenum alloy renowned for its exceptional high-temperature strength and oxidation resistance. This superalloy is widely used in demanding industrial applications where extreme conditions are present.
## Chemical Composition
The chemical composition of Hastelloy X plays a crucial role in its performance characteristics:
Element | Percentage
Nickel (Ni) | 47% (min)
Chromium (Cr) | 20.5-23%
Iron (Fe) | 17-20%
Molybdenum (Mo) | 8-10%
Cobalt (Co) | 0.5-2.5%
Tungsten (W) | 0.2-1%
Carbon (C) | 0.05-0.15%
## Physical Properties
Hastelloy X exhibits remarkable physical properties that make it suitable for high-temperature applications:
– Density: 8.22 g/cm³
– Melting Range: 1260-1355°C (2300-2475°F)
– Thermal Conductivity: 11.2 W/m·K at 100°C
– Electrical Resistivity: 1.22 μΩ·m at 20°C
## Mechanical Properties
The alloy demonstrates excellent mechanical properties across a wide temperature range:
– Tensile Strength: 655 MPa (95 ksi) at room temperature
– Yield Strength: 240 MPa (35 ksi) at room temperature
– Elongation: 35% at room temperature
– Creep Strength: Maintains strength at temperatures up to 1200°C (2200°F)
## Key Characteristics
Hastelloy X offers several distinctive features:
Keyword: Hastelloy X UNS N06002
– Outstanding oxidation resistance up to 1200°C (2200°F)
– Excellent resistance to carburizing and reducing atmospheres
– Good fabricability and weldability
– High strength retention at elevated temperatures
– Resistance to stress-corrosion cracking
## Industrial Applications
Due to its exceptional properties, Hastelloy X finds applications in various demanding industries:
### Aerospace Industry
– Combustion chambers
– Afterburner components
– Turbine casings
– Exhaust systems
### Industrial Gas Turbines
– Combustor liners
– Transition ducts
– Hot gas path components
### Petrochemical Industry
– Furnace components
– Catalyst grid supports
– Heat exchanger tubing
– Pyrolysis equipment
### Nuclear Industry
– High-temperature reactor components
– Heat exchangers
– Fuel element spacers
## Fabrication and Welding
Hastelloy X can be fabricated using standard techniques, though some considerations apply:
– Hot working should be performed between 1175-1230°C (2150-2250°F)
– Cold working requires intermediate annealing
– Welding can be performed using GTAW, GMAW, and SMAW methods
– Post-weld heat treatment is generally not required
## Comparison with Other Alloys
Hastelloy X offers distinct advantages compared to similar high-temperature alloys:
– Better oxidation resistance than Inconel 600
– Higher creep strength than Inconel 617
– Superior carburization resistance compared to Alloy 800H
– Better fabricability than some cobalt-based superalloys
## Maintenance and Corrosion Resistance
Proper maintenance ensures optimal performance of Hastelloy X components:
– Regular inspection for signs of thermal fatigue
– Monitoring for carburization in certain environments
– Cleaning with non-chlorinated solvents
– Avoiding contamination from other metals during maintenance
Hastelloy X UNS N06002 remains a premier choice for high-temperature applications where strength, oxidation resistance, and fabricability are
