Incoloy 825 is a nickel-iron-chromium alloy with additions of molybdenum,  copper and titanium. This nickel steel alloy’s chemical composition is designed  to provide exceptional resistance to many corrosive environments. It is similar  to alloy 800 but has improved resistance to aqueous corrosion. It has excellent  resistance to both reducing and oxidizing acids, to stress-corrosion cracking,  and to localized attack such as pitting and crevice corrosion. Alloy 825 is  especially resistant to sulfuric and phosphoric acids. This nickel steel alloy  is used for chemical processing, pollution-control equipment, oil and gas well  piping, nuclear fuel reprocessing, acid production, and pickling equipment.

What are the characteristics of Incoloy 825?

· Excellent resistance to reducing and oxidizing acids

· Good resistance to stress-corrosion cracking

· Satisfactory resistance to localized attack like pitting and crevice  corrosion

· Very resistant to sulfuric and phosphoric acids

· Good mechanical properties at both room and elevated temperatures up to  approximately 1000°F

· Permission for pressure-vessel use at wall temperatures up to 800°F

Alloy 825 (UNS N08825) Chemical Composition, %

Corrosion Resistance

Alloy 825 has a high level of corrosion resistance. It resists general  corrosion, pitting, crevice corrosion, intergranular corrosion, and  stress-corrosion cracking in both reducing and oxidizing environments.

In what applications is Incoloy 825 used?

· Chemical Processing

· Pollution-control

· Oil and gas well piping

· Nuclear fuel reprocessing

· Components in Pickling equipment like heating coils, tanks, baskets and  chains

· Acid production

ASTM Specifications

General Mechanical Properties

Alloy 825 has good mechanical properties from cryogenic temperatures to  moderately high temperatures. However, exposure to temperatures above 1000° F  can result in microstructural changes that significantly lower ductility and  impact strength. Alloy 825 should not be used at temperatures where  creep-rupture properties are design factors.