Introduction to Inconel 925
Inconel 925 is a high-performance nickel-iron-chromium alloy that belongs to the INCOLOY family. It is designed to provide a combination of high strength and excellent corrosion resistance, making it suitable for a wide range of demanding applications.
Chemical Composition
Inconel 925 is composed of nickel, chromium, molybdenum, copper, titanium, and aluminum. The specific composition ranges are as follows:
Mechanical Properties
Inconel 925 exhibits excellent mechanical properties, both at room temperature and in high-temperature environments:
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Tensile Strength: ≥1154 MPa (after solution annealing and aging)
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Yield Strength: ≥832 MPa (after solution annealing and aging)
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Elongation: ≥27% (after solution annealing and aging)
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Density: 8.08-8.14 g/cm³
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Melting Point: 1311-1366°C
Corrosion Resistance
Inconel 925 is highly resistant to various forms of corrosion, including:
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General Corrosion: It resists corrosion in both reducing and oxidizing environments.
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Pitting and Crevice Corrosion: The molybdenum and copper content enhance resistance to localized corrosion.
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Stress-Corrosion Cracking: The alloy is resistant to chloride-ion stress-corrosion cracking and sulfide stress cracking, making it suitable for use in sour (H₂S-containing) environments.
Applications
Due to its superior properties, Inconel 925 is widely used in the following industries:
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Aerospace: For components in jet engines and rocket engines.
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Oil and Gas: For down-hole and surface components, such as tubular products, valves, and hangers.
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Marine: For marine shafting and other components exposed to seawater.
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Chemical Processing: For equipment that handles corrosive chemicals like sulfuric acid and phosphoric acid.
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Nuclear Industry: For components in nuclear reactors.
Processing and Fabrication
Inconel 925 can be processed using various methods, including hot and cold working, welding, and heat treatment. The alloy is typically supplied in solution-annealed and aged condition to achieve its high strength. It is available in various forms, such as bars, plates, pipes, and forgings.
Conclusion
Inconel 925 is a versatile and reliable material, ideal for applications where high strength and corrosion resistance are critical. Its unique combination of properties makes it a preferred choice in many high-performance industries
Tensile Data
Mechanical Property Requirements |
| Ultimate Tensile | Yield Strength (0.2% OS) | Elong. in 2 in. or 50mm or 4D, min., % | R/A | Hardness |
Cold Worked/As worked |
Min | 110 KSi | 85 KSi | 10 |
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Min | 760 MPa | 585 KSi |
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Hot Worked/As worked |
Min | 90 KSi | 40 KSi | 25 |
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Max |
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Min | 620 MPa | 275 MPa |
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Max |
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D- Forging quality is furnished to chemical requirements and surface inspection only. No mechanical properties required.
Specifications
Form | Standard |
Metal Type | UNS N09925 |
Bar | ASTM B637 AMS 5662 |
Wire | ASTM B805 |
Sheet | ASTM B906 AMS 5664 |
Plate | ASTM B906 AMS 5664 |
Tube | ASTM B829 |
Pipe | ASTM B829 |
Fitting | ASTM B829 |
Forging | ASTM B670 |
Weld Wire |
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Weld Electrode |
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Din |
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Machining
Machinability Ratings
MACHINING DATA |
Carbide tools are suggested
for rates better than 50% of Type 304. |
Machining Type | Suggested starting rates are: |
Single Point turning : | Roughing - 0.15" depth, 0.015"/rev feed -175 SFM
Finishing - 0.025" depth, 0.007"/rev feed - 200 SFM |
Drilling : | 1/4" Dia hole - 0.004"/rev feed - 60 SFM
1/2" Dia hole - 0.007"/rev feed - 60 SFM
3/4" Dia hole - 0.010"/rev feed - 60 SFM |
Reaming : | Feed - same as drilling - 100 SFM |
Side and Slot Milling : | Roughing - 0.25" depth - 0.007"/tooth feed - 125SFM
Finishing - 0.050" depth - 0.009"/tooth feed - 140SFM |
These rates are for carbide tools,
Type C-2 for roughing, drilling and reaming.
Type C-3 for finishing. |