Description
Overview Of IN738
Inconel 738 powder is a cutting-edge nickel-based superalloy renowned for its exceptional strength, heat resistance, and corrosion resistance. Its advanced composition and superior mechanical properties make it indispensable across demanding industries such as aerospace, power generation, and industrial manufacturing. This in-depth overview explores its key characteristics, manufacturing processes, and versatility in real-world applications.
Powder Chemical Composition(wt,-%)
| Nickel | Balance |
| Chromium | 15 – 17 |
| Aluminum | 3.4 – 4.4 |
| Titanium | 3.2 – 4.2 |
| Iron | ≤12.5 |
| Cobalt | 8.5 – 10 |
| Molybdenum | 1.5 – 2.5 |
| Tantalum | 1 – 2 |
| Carbon | ≤0.11 |
Physical Properties
| Property | Value (Typical) |
| D10 (µm) | 18-22 µm |
| D50 (µm) | 32-38 µm |
| D90 (µm) | 48-53 µm |
| Hall Flow Rate | 25-35 s/50 g |
| Bulk Density (g/cm°) | 4.0-4.3 g/cm³ |
| Tap Density (g/cm°) | 4.8-5.2 g/cm³ |
Mechanical Properties
| Temperature | Tensile strength (MPa) | Vield strength (0.2% offset, MPa) | Elongation at Br |
| Room Temperature | 1100-1200 | 800-900 | 10-15 |
| 700°C | 950-1050 | 700-800 | 12-18 |
| 850°C | 650-750 | 500-600 | 15-25 |
| 980°c(short-term) | ≤400 | ≤300 | >25 |
Comparison of IN738 vs. Alternative Ni-Based Superalloy Powders
| Alloy | Oxidation Resistance | Cost | Printability | Weldability |
| IN738 | Excellent | Medium | Excellent | Good |
| IN718 | Medium | Low | Fair | Excellent |
| Haynes 282 | Excellent | Very High | Good | Limited |
| Inconel 625 | Good | Medium | Excellent | Excellent |
For additive manufacturing applications, IN738 delivers the best balance of printability and performance compared to alternatives like IN718 or Haynes 282, while offering competitive cost and reliability in extreme environments.
Key Takeaways
● IN738 excels in high-temperature oxidation resistance and additive manufacturing (AM) processes.
● IN718 is more economical but lags in printability.
● Haynes 282 has superior oxidation resistance but higher costs and limited weldability.
● Inconel 625 balances printability and weldability but lacks the thermal resistance of IN738.
For applications requiring both AM compatibility and extreme-service performance, IN738 is the preferred choice.
Primary Applications
● Aerospace: Turbine blades, nozzles, and combustion chamber components for jet engines and space systems.
● Power Generation: Gas turbine parts, steam turbine rotors, and heat exchangers in power plants.
● Industrial Manufacturing: Reactors, headers, and high-temperature pipelines in oil/gas and chemical processing.
● Additive Manufacturing: Complex, lightweight structures for performance-critical applications.
