Gnee Steel is a professional manufacturer of various Inconel 718, Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy 800, Incoloy 800H/HT, Incoloy 825, Monel 400, Monel K500, and other high-temperature alloy materials. The company specializes in the production and sales of alloy materials. Gnee Steel's products are widely used in aerospace, chemical, power generation, automotive, nuclear energy, and other fields, and the company can provide customized alloy material solutions according to customer needs.
Understanding the relationship between yield strength and temperature for Inconel 718 alloy
Understanding the relationship between yield strength and temperature for Inconel 718 alloy
Inconel 718 is a nickel-based superalloy that exhibits high yield strength at room temperature, typically exceeding 1100 MPa. Due to its precipitation-hardened microstructure, its strength gradually decreases with increasing temperature up to approximately 600-650°C. Although the strength decreases significantly above 700°C due to grain boundary weakening, the alloy maintains excellent creep rupture strength and structural integrity in demanding high-temperature environments.
What are the high-temperature properties of Inconel 718?
Inconel 718 is an age-hardenable nickel-based superalloy and one of the most commonly used alloys for aerospace engine components. IN718 was developed specifically for high-temperature applications, and therefore its design goals include maintaining strength at high temperatures, exhibiting good creep resistance, and having a good fatigue life up to 650 °C.
Chemical composition of Inconel 718 alloy
| Chemical Element | Content (wt. %) |
|---|---|
| Nickel (Ni) | 50.0 – 55.0 |
| Chromium (Cr) | 17.0 – 21.0 |
| Iron (Fe) | Balance |
| Niobium (Nb) | 4.75 – 5.50 |
| Molybdenum (Mo) | 2.80 – 3.30 |
| Titanium (Ti) | 0.65 – 1.15 |
| Aluminum (Al) | 0.20 – 0.80 |
| Cobalt (Co) | ≤ 1.0 |
| Carbon (C) | ≤ 0.08 |
| Manganese (Mn) | ≤ 0.35 |
| Silicon (Si) | ≤ 0.35 |
| Phosphorus (P) | ≤ 0.015 |
| Sulfur (S) | ≤ 0.015 |
| Boron (B) | ≤ 0.006 |
| Copper (Cu) | ≤ 0.30 |
Key Relationship Between Yield Strength and Temperature:
Room Temperature to 650°C (Stable Strength): Yield strength decreases slowly. For example, from approximately 1100-1300 MPa at room temperature to approximately 980 MPa at 650°C.
High-Temperature Performance (> 650°C): Above 650-700°C, the strength decreases rapidly, dropping to approximately 800 MPa at 700°C. This is due to the degradation of grain boundary strength and the coarsening of the strengthening phases γ' and γ''.
Low-Temperature Performance: Inconel 718 exhibits excellent performance at low temperatures, maintaining or even increasing strength and retaining ductility at sub-zero temperatures (e.g., -45°C to -70°C).
Yield Strength Anomaly (YSA): Some studies indicate an anomalous increase in yield strength of the 718 alloy in the 700-800°C range.
Microstructure Influence: High strength is primarily attributed to precipitation strengthening (γ'' phase). Prolonged exposure to temperatures above 650°C leads to coarsening of these precipitates, thus reducing yield strength.
Typical yield strength values (0.2% offset):
Room temperature: approximately 1100-1300 MPa
500°C (932°F): approximately 1000 MPa
650°C (1200°F): approximately 980 MPa
700°C (1292°F): approximately 800 MPa
760°C (1400°F): approximately 758 MPa
Gnee Steel also offers custom Inconel 718 products in various sizes and specifications. Please send us your drawings for a quotation!
Gnee Steel is a professional manufacturer of various nickel-based alloys, including Nickel 201, Nickel 202, Hastelloy C-276, Hastelloy C-22, Hastelloy B, Hastelloy C-4, Inconel Alloy 600, Inconel 625, Inconel 718, Inconel X-750, Incoloy Alloy 800, Incoloy 800H/HT, Incoloy 825, Monel Alloy 400, Monel K500, and high-temperature alloys. We specialize in the production and sales of alloy materials. Gnee Steel's products are widely used in aerospace, chemical, power, automotive, and nuclear energy industries, and we can provide customized alloy material solutions according to customer needs. For alloy material price inquiries or to request customized alloy material solutions, please feel free to contact us at ru@gneesteelgroup.com for a quote.