UNS R30188 Specification and Properties

# UNS R30188 Specification and Properties

## Introduction to UNS R30188

UNS R30188 is a high-performance alloy known for its exceptional strength and corrosion resistance. This alloy is commonly used in demanding applications where durability and reliability are critical. Its unique composition makes it suitable for aerospace, chemical processing, and other high-stress environments.

## Chemical Composition

The chemical composition of UNS R30188 plays a vital role in its performance characteristics. Below is a breakdown of its primary elements:

– Nickel (Ni): 50-55%
– Chromium (Cr): 20-23%
– Molybdenum (Mo): 8-10%
– Iron (Fe): 5% max
– Cobalt (Co): 1% max
– Tungsten (W): 0.2-1.0%
– Carbon (C): 0.05-0.15%
– Manganese (Mn): 1% max
– Silicon (Si): 1% max
– Phosphorus (P): 0.04% max
– Sulfur (S): 0.03% max

## Mechanical Properties

UNS R30188 exhibits outstanding mechanical properties that make it ideal for high-stress applications:

– Tensile Strength: 1200-1400 MPa
– Yield Strength: 800-1000 MPa
– Elongation: 15-25%
– Hardness: 30-40 HRC
– Fatigue Strength: Excellent
– Creep Resistance: Superior

## Physical Properties

The physical properties of UNS R30188 contribute to its performance in various environments:

– Density: 8.3 g/cm³
– Melting Point: 1350-1400°C
– Thermal Conductivity: 11.4 W/m·K
– Electrical Resistivity: 1.25 µΩ·m
– Coefficient of Thermal Expansion: 13.5 µm/m·K (20-100°C)

## Applications of UNS R30188

Due to its exceptional properties, UNS R30188 is used in several critical applications:

– Aerospace components (turbine blades, engine parts)
– Chemical processing equipment
– Oil and gas industry components
– Nuclear reactor components
– High-temperature fasteners
– Medical implants (in specific formulations)

## Heat Treatment and Fabrication

Proper heat treatment enhances the properties of UNS R30188:

– Solution Annealing: 1150-1200°C followed by rapid cooling
– Aging Treatment: 700-800°C for 4-8 hours
– Cold Working: Possible but requires annealing
– Welding: Possible with matching filler metals

## Corrosion Resistance

UNS R30188 offers excellent corrosion resistance in various environments:

– Resistance to oxidizing and reducing acids
– Excellent performance in chloride-containing environments
– Good resistance to pitting and crevice corrosion
– Maintains properties in high-temperature oxidizing atmospheres

## Comparison with Similar Alloys

When compared to similar high-performance alloys, UNS R30188 offers:

– Higher strength than Inconel 718
– Better creep resistance than Hastelloy X
– Superior oxidation resistance compared to Waspaloy
– More cost-effective than some cobalt-based superalloys

## Standards and Specifications

UNS R30188 meets several international standards:

– ASTM B637
– AMS 5666
– DIN 2.4668
– ISO 15156-3 (for oil and gas applications)

## Conclusion

UNS R30188 is a versatile high-performance alloy that combines excellent mechanical properties with outstanding corrosion resistance. Its unique combination of characteristics makes it indispensable in many demanding industrial applications. When selecting materials for extreme environments, UNS R30188 should be strongly considered for its reliability and performance.