Applications for Inconel 825
Incoloy 825 is a nickel-iron-chromium alloy that is widely used in the oil and gas and chemical process industries for its corrosion resistance and higher operating temperatures than most stainless steels.
What is Incoloy 825?
Incoloy is a trademark of Specialty Metals Corporation that refers to a family of nickel-iron-chromium alloys. These alloys were developed in the 1990s and include Alloy 825 (UNS N08825, 2.4858), Alloy 925 (UNS N09925), and Alloy 800. While the high-performance Inconel alloys were originally developed to support the development of the first generation of jet engines, Incoloy alloys were developed to provide a more cost-effective product - achieved by reducing the nickel content.
Alloy 825 has a nickel content of more than 40%, ensuring its resistance to stress corrosion cracking. Controlled additions of titanium inhibit intergranular corrosion that can occur at high temperatures. Additions of molybdenum and copper allow it to withstand reducing environments such as sulfuric and phosphoric acids, resulting in its widespread use in a variety of chemical process industry end uses.
What is Incoloy 825 used for?
Due to its good corrosion resistance and operating temperature range, it is used in oil and gas wellheads, risers, pipes, casing and tubing. Langley Alloys' supply chain partnerships mean that we can provide pipe, flanges and fittings in addition to solid bar. Solid bar is available from stock in diameters ranging from 3/4 inch to 10 inches.
Applications in the chemical process industry include thermowells and sensors, pump and valve components, hydrogen and ethylene furnaces, and components in fertilizer and ammonia plants. Typical components include vessels for handling seawater, ammonium sulfate, pickling acid, sulfuric acid and phosphoric acid.
Alloy 825 is also approved for use in pressure vessels with operating temperatures up to 525°C (AS1210, AS4041) and 538°C (ASME Boiler and Pressure Vessel Code, Sections I, III, VIII, IX, 1936 Case, N-188). Alloy 825 may form a brittle phase at temperatures above about 540°C and is not generally used at such temperatures where creep rupture performance is a design consideration.
