Incoloy 825 is an alloy having the composition of the nickel-iron-chromium alloy, along with additions of copper, titanium, and molybdenum. The chemical composition of this nickel steel alloy has been designed to provide incredible resistance to diverse many corrosive environments. While the Incoloy 825 is similar to alloy 800, it is able to provide superior resistance to aqueous corrosion than it. Alloy 825 is known to have high resistance to both oxidizing and reducing acids, as well as to stress-corrosion cracking. It also has commendable resistance to localized attacks like crevice and pitting corrosion. This nickel steel alloy is especially resistant to phosphoric and sulfuric acids and is commonly used for acid production, chemical processing, pickling equipment, pollution-control equipment, nuclear fuel reprocessing, as well as oil and gas well piping. Alloy 825 has emerged as a popular choice for alloy steel pipe fittings in various environments due to its good mechanical and corrosion resistance properties.

Alloy 825 (UNS N08825) Chemical Composition, %

38.0-46.022.0 min19.5-23.52.5-3.51.5-3.0.6-1.20.05 max1.0 max0.03 max0.5 max0.2 max

Corrosion Resistance

Incoloy alloy 825 has extremely high resistance in both oxidized and reducing environments. This alloy is able to resist general corrosion, stress-corrosion cracking, crevice corrosion, intergranular corrosion, and pitting. Owing to this incredible corrosion resistance capacity of this nickel steel alloy, it is extremely useful in environments having phosphoric acid, seawater, sulfuric acid, sulfur-containing flue gases, sour gas, and oil wells.



The products made of Incoloy 825 are treated during the manufacturing process at the mill in order to develop the optimum combination of formability, mechanical properties, stabilization, and corrosion resistance. For the purpose of maintaining these properties during the process of fabrication, successive anneals must be performed between a range of 930 to 980°C/1700 to 1800° followed by a process of rapid water quenching or air cooling. Conducting a heat temperate at the lower end of the range may also be suited. Annealing at temperatures in the higher end of this range can, however, be preferred for softness and deep-drawing while also maintaining corrosion resistance. While quenching is typically not needed for parts of thin cross-sections like wire, strips, and sheets, it is recommended in products having a heavier cross-section to avoid sensitization.

ASTM Specifications

Pipe SmlsPipe WeldedTube SmlsTube WeldedSheet/PlateBarForgingFitting
B423   B424B425B564B366, B564

General Mechanical Properties

Tensile (ksi).2% Yield (ksi)

Typical Mechanical Properties

MaterialForm and ConditionTensile Strength MPaYield Strength (0.2% Offset) MPaElongation (%)
Alloy 825 TubeAnnealed77244136
Alloy 825 TubeCold Drawn100088915
Alloy 825 BarAnnealed69032445
Alloy 825 PlateAnnealed66233845
Alloy 825 SheetAnnealed75842139

Incoloy 825 Melting Point

ElementDensityMelting PointTensile StrengthYield Strength (0.2%Offset)Elongation
Incoloy 8258.14 g/cm31400 °C (2550 °F)Psi – 80,000 , MPa – 550Psi – 32,000 , MPa – 22030 %

Incoloy 825 Equivalent

Incoloy 8252.4858N08825NCF 825NA 16ЭП703NFE30C20DUMNiCr21MoXH38BT

Key advantageous characteristics of Incoloy alloy 825

  • Commendable mechanical properties at the room, as well as elevated temperatures up to around 1000°F
  • Permission for pressure-vessel usage at wall temperatures up to 800°F
  • Excellent resistance to oxidizing and reducing acids
  • Great resistance to stress-corrosion cracking
  • Highly resistant to sulfuric and phosphoric acids


Common applications of Incoloy alloy 825

  • Propeller shafts
  • Ammonium sulphate vessels
  • Expansion bellows
  • Marine exhaust systems
  • Tank trucks
  • Calorifiers
  • Sulphuric acid piping and vessels
  • Phosphoric acid evaporators
  • Pickling tank heaters and equipment
  • Chemical process equipment
  • Electrostatic precipitator electrodes
  • Hot vessels for seawater, food, and water

Midland Alloys is among the most renowned suppliers of alloy steel pipe fittings, including the ones made with Incoloy alloy 825. This company is famed for supplying high-performance metal alloys to a host of diverse industries. Being a widely respected and well-established European supplier, Midland Alloys is known to offer the finest quality of corrosion-resistant, heat resistant, titanium and stainless steel alloys in both international and national markets.

We offer high quality, lower cost but the best service. As a result to that our export account today is in over 45 countries some of them are United States, United Arab Emirates, Canada, Pakistan, Spain, France, United Kingdom, Indonesia, Iran, Kuwait, Mexico, Malaysia, Nigeria, Singapore, Saudi Arabia, Netherlands, Brazil, Colombia, Egypt, Iraq, Sri Lanka, Russia, Vietnam, South Africa,, Nigeria, Turkey, Bangladesh, Italy, Japan, Thailand, Hong Kong, Switzerland, New Zealand We welcome your inquiries.