# UNS N07090 Alloy Properties and Applications

## Introduction to UNS N07090 Alloy

UNS N07090 is a nickel-based superalloy known for its exceptional high-temperature strength and corrosion resistance. This alloy is part of a family of materials designed to withstand extreme environments, making it a popular choice in aerospace, power generation, and chemical processing industries.

## Chemical Composition

The chemical composition of UNS N07090 plays a crucial role in its performance characteristics:

– Nickel (Ni): 58-63%

– Chromium (Cr): 19-23%
– Cobalt (Co): 13-16%
– Molybdenum (Mo): 4-6%
– Aluminum (Al): 1.4-1.8%
– Titanium (Ti): 2.8-3.3%
– Iron (Fe): ≤1.0%
– Carbon (C): ≤0.08%
– Boron (B): ≤0.008%
– Zirconium (Zr): ≤0.06%

## Mechanical Properties

UNS N07090 exhibits impressive mechanical properties, especially at elevated temperatures:

– Tensile Strength: 1200-1400 MPa at room temperature
– Yield Strength: 800-1000 MPa at room temperature
– Elongation: 10-15% at room temperature
– Creep Resistance: Excellent performance up to 980°C (1800°F)
– Fatigue Strength: Superior resistance to cyclic loading

## Physical Properties

The physical characteristics of UNS N07090 include:

– Density: 8.19 g/cm³
– Melting Range: 1290-1345°C (2350-2450°F)
– Thermal Expansion Coefficient: 12.6 μm/m·°C (20-1000°C)
– Thermal Conductivity: 11.4 W/m·K at 100°C
– Electrical Resistivity: 1.25 μΩ·m at 20°C

## Heat Treatment

Proper heat treatment is essential for optimizing the properties of UNS N07090:

– Solution Annealing: Typically performed at 1080-1120°C (1975-2050°F) followed by rapid cooling
– Aging Treatment: Usually conducted at 700-800°C (1290-1470°F) for 16 hours
– Stress Relieving: Recommended after machining operations

## Corrosion Resistance

UNS N07090 offers excellent corrosion resistance in various environments:

– Oxidation resistance up to 1100°C (2010°F)
– Resistance to sulfidation and carburization
– Good performance in reducing and oxidizing atmospheres
– Resistance to hot corrosion in gas turbine environments

## Fabrication and Machining

Working with UNS N07090 requires special considerations:

– Machinability: Similar to other nickel-based superalloys (approximately 15% of free machining steel)
– Welding: Can be welded using TIG or electron beam methods with matching filler metal
– Forming: Requires hot forming above 980°C (1800°F) for significant deformation
– Grinding: Recommended for final machining operations

## Applications of UNS N07090

This alloy finds use in numerous demanding applications:

### Aerospace Industry

– Turbine blades and vanes
– Combustion chambers
– Afterburner components
– Exhaust systems

### Power Generation

– Gas turbine components
– Steam turbine blades
– Nuclear reactor parts
– Heat exchangers

### Industrial Applications

– Chemical processing equipment
– High-temperature fasteners
– Furnace components
– Oil and gas downhole tools

## Advantages of UNS N07090

The key benefits of this alloy include:

– Exceptional high-temperature strength
– Outstanding creep resistance
– Good thermal fatigue properties
– Excellent oxidation and corrosion resistance