# UNS R30188 Material Specification and Properties
## Introduction to UNS R30188
UNS R30188 is a high-performance cobalt-based alloy that finds extensive use in demanding applications across various industries. This material is known for its exceptional combination of strength, corrosion resistance, and high-temperature performance.
## Chemical Composition
The chemical composition of UNS R30188 plays a crucial role in determining its properties:
Element | Percentage
Cobalt (Co) | Balance
Chromium (Cr) | 19-21%
Nickel (Ni) | 9-11%
Tungsten (W) | 14-16%
Iron (Fe) | ≤3%
Carbon (C) | 0.05-0.15%
Manganese (Mn) | ≤1%
Silicon (Si) | ≤1%
## Mechanical Properties
UNS R30188 exhibits impressive mechanical characteristics:
– Tensile Strength: 1200-1400 MPa
– Yield Strength: 800-1000 MPa
Keyword: uns r30188
– Elongation: 10-15%
– Hardness: 35-45 HRC
– Fatigue Strength: Excellent at elevated temperatures
## Physical Properties
The physical properties of UNS R30188 include:
– Density: 9.13 g/cm³
– Melting Range: 1290-1350°C (2354-2462°F)
– Thermal Conductivity: 14.6 W/m·K at 100°C
– Electrical Resistivity: 1.05 μΩ·m at 20°C
– Coefficient of Thermal Expansion: 12.3 μm/m·K (20-100°C)
## Heat Treatment and Processing
UNS R30188 can be processed through various methods:
– Solution annealing at 1175-1230°C followed by rapid cooling
– Stress relieving at 870-900°C
– Cold working possible but requires annealing
– Machinability rating: 20% compared to 100% for free-cutting steel
## Corrosion Resistance
The alloy demonstrates excellent corrosion resistance properties:
– Outstanding resistance to oxidizing and reducing acids
– Good performance in chloride-containing environments
– Superior resistance to pitting and crevice corrosion
– Maintains corrosion resistance at elevated temperatures
## Applications of UNS R30188
This material is commonly used in:
– Aerospace components
– Gas turbine engine parts
– Chemical processing equipment
– Nuclear reactor components
– Medical implants
– High-temperature fasteners
## Advantages Over Other Alloys
UNS R30188 offers several benefits compared to similar materials:
– Better high-temperature strength than nickel-based alloys
– Superior wear resistance compared to stainless steels
– Excellent thermal fatigue resistance
– Good fabricability despite high strength
– Long-term stability in extreme environments
## Limitations and Considerations
While UNS R30188 is an exceptional material, some factors should be considered:
– Higher cost compared to standard alloys
– Requires specialized machining techniques
– Limited availability in some forms
– Potential for work hardening during processing
– May require post-weld heat treatment
## Standards and Specifications
UNS R30188 is covered by various industry standards:
– ASTM F90 (wrought cobalt-chromium-tungsten-nickel alloy)
– AMS 5536 (for bar, forgings, and rings)
– ISO 5832-5 (for surgical implants)
– MIL-S-25043 (for aerospace applications)
## Future Developments
Research continues to enhance UNS R30188 properties:
– Improved processing techniques for better consistency
– Development of additive manufacturing methods
– Surface treatment advancements for specialized applications
– Alloy modifications for specific industry needs
– Recycling and sustainability initiatives