Inconel Alloys
Inconel 725 (UNS N07725) — Composition, Properties & Supply
Inconel 725 (UNS N07725) combines the corrosion resistance of Inconel 625 with age-hardening strength — roughly twice the yield of 625 — making it the preferred choice for sour downhole tools, high-strength fasteners and valve stems.
What is the chemical composition of Inconel 725?
| Element | Symbol | Content (wt%) |
|---|---|---|
| Ni | Ni | 55.0–59.0 |
| Cr | Cr | 19.0–22.5 |
| Mo | Mo | 7.0–9.5 |
| Nb | Nb | 2.75–4.00 |
| Ti | Ti | 1.00–1.70 |
| Fe | Fe | Balance |
| Al | Al | ≤ 0.35 |
| C | C | ≤ 0.03 |
| Mn | Mn | ≤ 0.35 |
| Si | Si | ≤ 0.20 |
Values are typical specification limits. Actual heat analysis is reported on the EN 10204 3.1 mill test certificate supplied with each shipment.
What are the mechanical properties of Inconel 725?
| Property | Value | Note |
|---|---|---|
| Tensile strength | ≥ 1137 MPa (aged) | Room temperature |
| Yield strength (0.2% offset) | ≥ 827 MPa (aged) | Room temperature |
| Elongation | ≥ 20 % | Gauge length 50 mm / 4D |
| Hardness | ≥ 32 HRC | Brinell / Rockwell |
What are the physical properties of Inconel 725?
| Property | Value |
|---|---|
| Density | 8.31 g/cm³ |
| Melting range | 1271–1343 °C |
| Thermal conductivity | 10.6 W/m·K |
| Elastic modulus | 204 GPa |
| Maximum service temperature | 650 °C |
What are the key characteristics of Inconel 725?
- Age-hardened yield around 827 MPa, about twice that of 625
- Retains 625-class pitting and crevice corrosion resistance
- Meets NACE MR0175 for the most severe sour service levels
- Resistant to hydrogen embrittlement and sulphide stress cracking
Where is Inconel 725 used?
- Sour oil and gas downhole tools, packers and hangers
- High-strength valve stems, fasteners and lifting gear
- High-strength shafts for corrosive chemical service
- Offshore mooring and tensioner components
Which standards and specifications cover Inconel 725?
- ASTM B805
- NACE MR0175 / ISO 15156
- UNS N07725
What product forms are available?
Frequently asked questions
What advantage does Inconel 725 have over 718?
725 carries more chromium and molybdenum (Cr 19–22.5%, Mo 7–9.5%), so it is clearly more corrosion resistant than 718 while ageing to comparable strength via Ti and Nb. Where NACE MR0175 sour compliance and 718-class strength are both required, 725 is the stronger answer.
Need Inconel 725 bar, tube, plate or forgings?
Send the grade, dimensions, standard and quantity. We answer within 10 minutes on working days and quote within 24 hours, with EN 10204 3.1 certification.
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