# UNS R30188 Specification and Properties

## Introduction to UNS R30188

UNS R30188 is a high-performance nickel-based superalloy known for its exceptional strength and resistance to oxidation and corrosion at elevated temperatures. This alloy is widely used in aerospace, power generation, and industrial applications where extreme conditions are present.

## Chemical Composition

Keyword: uns r30188

The chemical composition of UNS R30188 plays a crucial role in its performance characteristics:

– Nickel (Ni): 58-63%
– Chromium (Cr): 19-23%
– Cobalt (Co): 13-16%
– Molybdenum (Mo): 4-6%
– Tungsten (W): 3-5%
– Aluminum (Al): 1.4-1.8%
– Titanium (Ti): 2.5-3.3%
– Carbon (C): 0.05-0.15%
– Boron (B): 0.003-0.010%
– Zirconium (Zr): 0.03-0.08%

## Mechanical Properties

UNS R30188 exhibits outstanding mechanical properties, especially at high temperatures:

### Room Temperature Properties

– Tensile Strength: 1200-1400 MPa
– Yield Strength: 800-950 MPa
– Elongation: 10-15%
– Hardness: 35-40 HRC

### Elevated Temperature Properties (650°C)

– Tensile Strength: 900-1100 MPa
– Yield Strength: 700-850 MPa
– Creep Resistance: Excellent
– Fatigue Strength: Superior

## Physical Properties

The physical characteristics of UNS R30188 include:

– Density: 8.3 g/cm³
– Melting Range: 1290-1350°C
– Thermal Conductivity: 11.4 W/m·K at 100°C
– Electrical Resistivity: 1.25 μΩ·m at 20°C
– Coefficient of Thermal Expansion: 13.3 μm/m·K (20-100°C)

## Applications

UNS R30188 is utilized in various demanding applications:

– Aircraft turbine engine components
– Industrial gas turbine parts
– Nuclear reactor components
– High-temperature fasteners
– Chemical processing equipment
– Power generation systems

## Heat Treatment

Proper heat treatment is essential for optimizing the properties of UNS R30188:

1. Solution Annealing: 1080-1120°C followed by rapid cooling
2. Aging Treatment: 760-800°C for 16 hours, air cool
3. Stress Relieving: 870-900°C for 2 hours, slow cool

## Fabrication and Machining

Working with UNS R30188 requires special considerations:

– Machining: Requires rigid setups and carbide tools
– Welding: Possible using matching filler metals
– Forming: Best performed at elevated temperatures
– Grinding: Use proper coolant and wheel selection

## Corrosion Resistance

UNS R30188 offers excellent resistance to:

– Oxidation at temperatures up to 1100°C
– Sulfidation in reducing environments
– Hot corrosion in salt-containing atmospheres
– Stress corrosion cracking in chloride environments

## Standards and Specifications

UNS R30188 conforms to various industry standards:

– ASTM: B637, B670
– AMS: 5666, 5667
– UNS: R30188
– DIN: 2.4675
– EN: NiCr19Co15Mo4Ti3Al1BZr

## Comparison with Other Superalloys

When compared to similar alloys, UNS R30188 offers:

– Better creep strength than Inconel 718
– Higher temperature capability than Waspaloy
– Superior oxidation resistance compared to Rene 41
– Better fabricability than Mar

By