Cobalt Nickel 188 Sheet in India, Cobalt Nickel 188 Sheet Importers in India, Cobalt Nickel 188 Sheet Suppliers in India, Cobalt Nickel 188 Sheet Exporter in India, Cobalt Nickel 188 Sheet Stockists in India.
Alloy 188, also known as Haynes® 188, Nickel Alloy 188, and Udimet 188®, is a high-performance cobalt-nickel-chromium-tungsten superalloy. This alloy is notable for its excellent high-temperature strength, oxidation resistance, and resistance to sulfidation, making it ideal for demanding applications such as aerospace and gas turbine engines.
Key Features of Alloy 188
- High-Temperature Strength: Alloy 188 maintains its strength at elevated temperatures up to 2000°F (1095°C), making it suitable for high-stress, high-heat environments.
- Oxidation and Sulfidation Resistance: The alloy exhibits excellent resistance to oxidation and sulfidation, which is crucial for maintaining integrity and performance in harsh environments.
- Fabrication: Alloy 188 is versatile in terms of fabrication, as it can be readily cold and hot worked. It offers outstanding ductility and metallurgical stability, facilitating various manufacturing processes.
Chemical Composition
| Element | Content (%) |
|---|---|
| Cobalt (Co) | Balance (≥ 37) |
| Nickel (Ni) | 20.0 – 24.0 |
| Chromium (Cr) | 21.0 – 23.0 |
| Tungsten (W) | 13.0 – 15.0 |
| Iron (Fe) | ≤ 3.0 |
| Manganese (Mn) | ≤ 1.25 |
| Silicon (Si) | 0.20 – 0.50 |
| Carbon (C) | 0.05 – 0.15 |
| Lanthanum (La) | 0.03 – 0.12 |
| Phosphorous (P) | ≤ 0.02 |
| Sulfur (S) | ≤ 0.015 |
Physical Properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.9 g/cm³ | 0.324 lb/in³ |
| Melting Point | 1330°C | 2425°F |
| Incipient Fusion Temperature | 1302-1330°C | 2375-2425°F |
| Electrical Resistivity | 1.01 microhm-m | 39.6 microhm-in. |
| Coefficient of Thermal Expansion (70-2000°F) | 18.5 x 10⁻⁶ m/m-K | 10.3 microin./in.-°F |
| Thermal Conductivity | 21.9 W/m-K | 152 Btu-in/ft²-hr-°F |
| Thermal Diffusivity | 5.8 x 10⁻⁶ m²/s | 0.009 in²/sec |
Mechanical Properties
At Room Temperature (RT):
- Extruded Bar (Solution Treated – AMS 5772):
Property Value Yield Strength (0.2% Offset) 379 MPa (55 ksi) Tensile Strength 862 MPa (125 ksi) Elongation (%) 45 Hardness ≤ 302 HB - Sheet (Solution Treated – AMS 5608):
Thickness Value ≤ 0.020″ Yield Strength 379 MPa (55 ksi) ≤ 0.020″ Tensile Strength 862 MPa (125 ksi) ≤ 0.020″ Elongation (%) 40 ≥ 0.020″ Yield Strength 379 MPa (55 ksi) ≥ 0.020″ Tensile Strength 862 MPa (125 ksi) ≥ 0.020″ Elongation (%) 45 Hardness HRC –
At Elevated Temperatures (1200°F):
- Sheet (Solution Treated – AMS 5608):
Thickness Value ≤ 0.020″ Yield Strength 248 MPa (36 ksi) ≤ 0.020″ Tensile Strength 621 MPa (90 ksi) ≤ 0.020″ Elongation (%) 40 ≥ 0.020″ Yield Strength 248 MPa (36 ksi) ≥ 0.020″ Tensile Strength 621 MPa (90 ksi) ≥ 0.020″ Elongation (%) 50 Hardness HRC –
Equivalents and Specifications
- AMS 5608: Covers Haynes 188™ in sheet form.
- AMS 5772: Covers Haynes 188™ in bars, forgings, and forging stock.
- GE B50A712, GE B50TF74, GE B50TF74A: Specifications used by General Electric.
- PWA 1042: Specification used by Pratt & Whitney.
Applications
Due to its excellent high-temperature performance and resistance to oxidation and sulfidation, Alloy 188 is widely used in:
- Aerospace components such as combustion cans, flame holders, liners, transition ducts, and afterburner parts.
- Gas turbine engines where high-temperature stability and strength are critical.
Summary
Alloy 188, or Haynes® 188, is a robust cobalt-based superalloy designed for high-temperature applications. It offers a unique combination of high-temperature strength, oxidation resistance, and ease of fabrication, making it a preferred material in aerospace and industrial gas turbine applications.
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