# UNS R30188 Specification and Properties
## Introduction to UNS R30188
UNS R30188 is a high-performance nickel-based alloy known for its exceptional resistance to oxidation and corrosion at elevated temperatures. This alloy is widely used in aerospace, chemical processing, and power generation industries where materials must withstand extreme environments.
## Chemical Composition
Keyword: uns r30188
The chemical composition of UNS R30188 plays a crucial role in its performance characteristics:
Element | Percentage
Nickel (Ni) | 58-63%
Chromium (Cr) | 20-23%
Cobalt (Co) | 5-7%
Tungsten (W) | 13-15%
Molybdenum (Mo) | 1-2%
Aluminum (Al) | 0.5-1.5%
Titanium (Ti) | 0.5-1.5%
Iron (Fe) | ≤3%
Carbon (C) | ≤0.15%
## Mechanical Properties
UNS R30188 exhibits excellent mechanical properties across a wide temperature range:
– Tensile Strength: 1200-1400 MPa at room temperature
– Yield Strength: 800-1000 MPa at room temperature
– Elongation: 15-25% in 50 mm
– Hardness: 30-40 HRC
– Creep Resistance: Excellent performance up to 1000°C (1832°F)
## Physical Properties
The physical characteristics of UNS R30188 include:
– Density: 8.9 g/cm³
– Melting Point: 1350-1400°C (2462-2552°F)
– 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 (20-1000°C)
## Applications
Due to its unique combination of properties, UNS R30188 finds applications in:
– Gas turbine engine components
– Combustion chambers
– Afterburner parts
– Industrial furnace components
– Chemical processing equipment
– Nuclear reactor components
## Fabrication and Heat Treatment
UNS R30188 can be fabricated using standard methods, though it requires specialized techniques due to its high strength:
– Hot Working: Performed between 1050-1200°C (1922-2192°F)
– Cold Working: Possible but requires intermediate annealing
– Welding: Recommended methods include GTAW and PAW
– Heat Treatment: Solution annealing at 1150-1200°C (2102-2192°F) followed by rapid cooling
## Corrosion Resistance
The alloy offers outstanding corrosion resistance in various environments:
– Excellent oxidation resistance up to 1100°C (2012°F)
– Good resistance to sulfidation
– Performs well in carburizing environments
– Resistant to chloride-ion stress-corrosion cracking
## Standards and Specifications
UNS R30188 is covered by several international standards:
– ASTM B435 – Sheet, strip, and plate
– ASTM B572 – Rod and bar
– AMS 5537 – Aerospace material specification
– ISO 6208 – International standard
## Comparison with Similar Alloys
When compared to other high-temperature alloys:
– Better oxidation resistance than Inconel 718
– Higher creep strength than Hastelloy X
– Superior thermal fatigue resistance compared to Waspaloy
– More expensive than 304 stainless steel but offers far better high-temperature performance
## Conclusion
UNS R30188 represents a premium material solution for applications demanding exceptional high-temperature strength, oxidation resistance, and creep performance. While its cost is higher than many alternatives, its performance in extreme environments justifies the investment for critical applications where
