ATI 825 alloy (UNS N08825) is an austenitic nickel-iron-chromium-molybdenum-copper alloy containing high levels of chromium, nickel, molybdenum and copper to provide high levels of corrosion resistance to both moderately oxidizing and moderately reducing environments. The alloy has a high level of nickel, which in combination with the level of molybdenum and copper, produces substantially improved corrosion resistance in reducing environments compared to the standard stainless steels. Higher chromium alloys such as E-BRITE® 26-1 alloy (S44627) or Type 310 should be specified in the most severely oxidizing environments typified by hot nitric acid at concentrations near the azeotrope. The nickel content is sufficiently high to provide superb resistance to chloride stress corrosion cracking. The chromium and molybdenum content of the alloy provides a level of resistance to chloride ion pitting, however, not to the level of other Allegheny Ludlum alloys like AL-6XN® (N08367), AL 29-4C® (S44735) or ATI 625 (N06625) alloys. In addition, the alloy is stabilized against sensitization in the welded condition by the addition of a specified level of titanium. Because of this stabilization, the material is resistant to intergranular attack after exposure in the temperature range which would sensitize unstabilized stainless steels.

The N08825 alloy has a long history of use in many corrosive environments and has been incorporated in ASTM and ASME specifications for many years. As an austenitic, nickel-base alloy, the material is ductile over a wide range of temperatures from cryogenic to well in excess of 1000°F (538°C). Fabricability is typical of nickel-base alloys, with the material readily formable and weldable by a variety of techniques.