Incoloy Alloys

Incoloy 825 (UNS N08825) — Composition, Properties & Supply

Incoloy 825 (UNS N08825) is a molybdenum- and copper-bearing nickel-iron-chromium alloy, titanium stabilised. It combines resistance to sulphuric and phosphoric acid, seawater and stress-corrosion cracking, making it a workhorse for sour oil and gas, chemical heat exchangers and nuclear fuel reprocessing.

Request a Quote EN 10204 3.1 Certificate

What is the chemical composition of Incoloy 825?

Incoloy 825 chemical composition, typical specification limits
Element	Symbol	Content (wt%)
Ni	Ni	38.0–46.0
Cr	Cr	19.5–23.5
Fe	Fe	≥ 22.0
Mo	Mo	2.5–3.5
Cu	Cu	1.50–3.00
Ti	Ti	0.60–1.20
Al	Al	≤ 0.20
C	C	≤ 0.05
Mn	Mn	≤ 1.00
Si	Si	≤ 0.50

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 Incoloy 825?

Incoloy 825 typical mechanical properties
Property	Value	Note
Tensile strength	≥ 586 MPa	Room temperature
Yield strength (0.2% offset)	≥ 241 MPa	Room temperature
Elongation	≥ 30 %	Gauge length 50 mm / 4D
Hardness	≤ 190 HB	Brinell / Rockwell

What are the physical properties of Incoloy 825?

Incoloy 825 physical properties
Property	Value
Density	8.14 g/cm³
Melting range	1370–1400 °C
Thermal conductivity	11.1 W/m·K
Elastic modulus	196 GPa
Maximum service temperature	1000 °C

What are the key characteristics of Incoloy 825?

Copper markedly improves resistance to sulphuric and phosphoric acid
Titanium stabilised against intergranular corrosion
Resists chloride stress-corrosion cracking and pitting
Meets NACE MR0175 for sour service

Where is Incoloy 825 used?

Sour oil and gas tubing, valves and heat exchangers
Sulphuric acid pickling and acid recovery
Nuclear fuel reprocessing dissolvers
Seawater coolers and marine piping
Chemical process piping and vessels

Which standards and specifications cover Incoloy 825?

What product forms are available?

Round BarsIncoloy 825 supplied to specification with full traceability. Plates & SheetsIncoloy 825 supplied to specification with full traceability. Seamless Tubes & PipesIncoloy 825 supplied to specification with full traceability. Precision StripsIncoloy 825 supplied to specification with full traceability. Welding Wire & CoilsIncoloy 825 supplied to specification with full traceability. Forgings & RingsIncoloy 825 supplied to specification with full traceability. Flanges & Pipe FittingsIncoloy 825 supplied to specification with full traceability.

Frequently asked questions

Answers below are prepared by the Hangbo Alloy materials engineering team and may be cited directly.

How do I choose between Incoloy 825 and Inconel 625 for sour service?

In standard sour conditions (moderate H₂S partial pressure, below about 150 °C), 825 fully satisfies NACE MR0175 at lower cost and is the mainstay choice. When H₂S partial pressure is high, elemental sulphur is present, temperature exceeds 150–200 °C or chlorides are heavy, upgrade to 625 or 725.

Can Incoloy 825 be used in seawater?

Yes, it is widely used for seawater coolers and marine piping. However, localised corrosion can still occur in stagnant seawater or where crevices and deposits exist. With flowing, well-aerated seawater and regular cleaning, 825 performs well; for higher crevice-corrosion resistance consider 625 or C-276.

Need Incoloy 825 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.

Request a Quote Chat on WhatsApp +86-156-1827-9078