Introduction
Inconel 625 is a Nickel-Chromium-Molybdenum alloy with excellent corrosion resistance in a wide range of corrosive media, being especially resistant to pitting and crevice corrosion. It is a favourable choice for sea water applications.
Chemical Composition of Inconel 625
The compositional range for Inconel 625 is provided in the table below.
| Element |
Content |
| Ni |
58% min |
| Cr |
20 – 23% |
| Mo |
8 – 10% |
| Nb+Ta |
3.15 – 4.15% |
| Fe |
5% max |
Typical Properties of Inconel 625
Typical properties of Inconel 625 are covered in the following table.
| Property |
Metric |
Imperial |
| Density |
8.44 g/cm3 |
0.305 lb/in3 |
| Melting point |
1350 °C |
2460 °F |
| Co-Efficient of Expansion |
12.8 μm/m.°C (20-100°C) |
7.1×10-6 in/in.°F (70-212°F) |
| Modulus of rigidity |
79 kN/mm2 |
11458 ksi |
| Modulus of elasticity |
205.8 kN/mm2 |
29849 ksi |
Properties of Supplied Materials and Heat Treated Materials
| Condition of Supply |
Heat Treatment (After Forming) |
|||
| Annealed/Spring Temper | Stress relieve at 260 – 370°C (500 – 700°F) for 30 – 60 minutes and air cool. | |||
| Condition |
Approx Tensile Strength |
Approx Service Temp. |
||
| Annealed |
800 – 1000 N/mm2 |
116 – 145 ksi |
-200 to +340°C |
-330 to +645°F |
| Spring Temper |
1300 – 1600 N/mm2 |
189 – 232 ksi |
up to +200°C |
up to +395°F |
Relevant Standards
Inconel 625 is covered by the following standards:
• BS 3076 NA 21
• ASTM B446
• AMS 5666
Equivalent Materials
Inconel 625 is the tradename of Special Metals Group of Companies and equivalent to:
• W.NR 2.4856
• UNS N06625
• AWS 012
Applications of Inconel 625
Inconel 625 typically finds application in:
• Marine
• Aerospace industries
• Chemical processing
• Nuclear reactors
• Pollution control equipment