Inconel 600, 625 & 825 Flanges & Fittings
Nickel–chromium alloys hold their strength and resist oxidation, carburisation and chloride stress corrosion cracking from cryogenic temperatures to well above 900 °C.
Teshi Group manufactures Inconel 600, 625 and 825 flanges to ASTM B564 and butt weld fittings to ASTM B366, with PMI on every piece and full heat traceability.
Inconel — grades, chemistry and properties
Grades and ASTM / ASME specifications
| Grade | Forged flanges & fittings | Butt weld fittings | Plate | Pipe |
|---|---|---|---|---|
| Alloy 600UNS N06600 · W.Nr. 2.4816 | ASTM B564 N06600 | ASTM B366 WPNCI | ASTM B168 | ASTM B167 |
| Alloy 625UNS N06625 · W.Nr. 2.4856 | ASTM B564 N06625 | ASTM B366 WPNCMC | ASTM B443 | ASTM B444 |
| Alloy 825UNS N08825 · W.Nr. 2.4858 | ASTM B564 N08825 | ASTM B366 WPNICMC | ASTM B424 | ASTM B423 |
Chemical composition (weight %, maximum unless a range is given)
| Grade | C | Mn | Si | Cr | Ni | Mo | Cu | Nb | Ti | Fe |
|---|---|---|---|---|---|---|---|---|---|---|
| Alloy 600 | 0.15 | 1.00 | 0.50 | 14.0–17.0 | 72.0 min | — | 0.50 | — | — | 6.0–10.0 |
| Alloy 625 | 0.10 | — | — | 20.0–23.0 | 58.0 min | 8.0–10.0 | — | 3.15–4.15 (Nb+Ta) | — | 5.0 |
| Alloy 825 | 0.05 | — | — | 19.5–23.5 | 38.0–46.0 | 2.5–3.5 | 1.5–3.0 | — | 0.6–1.2 | 22.0 min |
Mechanical properties (minimum, room temperature)
| Grade | Tensile strength | Yield strength (0.2 %) | Elongation | Note |
|---|---|---|---|---|
| Alloy 600 | 550 MPa (80 ksi) | 240 MPa (35 ksi) | 30 % | Annealed |
| Alloy 625 | 827 MPa (120 ksi) | 414 MPa (60 ksi) | 30 % | Annealed |
| Alloy 825 | 586 MPa (85 ksi) | 241 MPa (35 ksi) | 30 % | Annealed |
Values are minimums and limits from the governing ASTM / ASME specifications, summarised for convenience. The current edition of the specification takes precedence; confirm requirements against your project specification.
Where it is used
- Furnace, heater and high-temperature process piping
- Sour gas and oil well equipment (825, 625)
- Sulphuric and phosphoric acid service (825)
- Seawater and chloride service (625)
- Chemical and petrochemical reactors
Testing & certification
- PMI on every piece
- Intergranular corrosion testing to ASTM G28 when specified
- Ultrasonic testing of forgings when specified
- EN 10204 3.1 certificate; 3.2 on request
Inconel products we manufacture
All products
01OEM manufacturerWeld Neck Flanges
ASME B16.5 · ASME B16.47
02OEM manufacturerBlind Flanges
ASME B16.5 · ASME B16.47
03OEM manufacturerSlip-On Flanges
ASME B16.5 · EN 1092-1 Type 12
04OEM manufacturerButt Weld Elbows
ASME B16.9 · ASME B16.25
05OEM manufacturerButt Weld Tees
ASME B16.9 · ASME B16.25
06OEM manufacturerWeldolets & Sockolets
MSS SP-97 · ASME B16.11
FAQ
Inconel: common questions
Which specification covers Inconel flanges?
Nickel alloy forgings including Inconel 600, 625 and 825 flanges are made to ASTM B564 / ASME SB564; butt weld fittings to ASTM B366 / ASME SB366.
What is the strength of Inconel 625?
Annealed alloy 625 (UNS N06625) forgings to ASTM B564 have a minimum tensile strength of 827 MPa and yield strength of 414 MPa.
Where is Incoloy / Inconel 825 used?
Alloy 825 (UNS N08825) is used for sulphuric and phosphoric acid, sour gas wells and pickling plants, where its nickel, molybdenum and copper resist both reducing and oxidising acids.
Do you test nickel alloy flanges for intergranular corrosion?
Yes, when specified. ASTM G28 testing is arranged for alloys such as 625, C-276 and C-22, and results are reported on the certificate.
Ready to build to spec?
Share your drawing, bill of materials or technical requirements with the Teshi team.