Carlson Alloy C 800AT Nickel-Iron-Chromium Alloy

Subcategory: Superalloy; Nickel Alloy

Key Words: UNS N08811

Material Notes:
General Description

Carlson Alloy C 800AT is a modification of Carlson Alloy C 800, exhibiting higher creep and rupture strengths. This nickel-iron-chromium alloy has a carbon content restricted to a range of 0.06 to 0.10%. The aluminum plus titanium content of this alloy is also maintained in the upper portion of the standard range (0.85 to 1.20%).

C 800AT is solution-annealed at 2100°F (1500°C). That heat treatment and the compositional restrictions are responsible for this alloy’s improved creep and rupture strengths.

Since the chemistry of C 800AT falls within the range of C 800, there are no significant differences in physical and thermal properties. The major differences between the alloys are in the mechanical properties. (Generally C 800 exhibits higher mechanical properties at room temperature and during short-term exposure to elevated temperatures.) C 800AT displays superior and rupture strengths over long-term exposure to elevated temperatures.

C 800AT offers higher ASME boiler and pressure vessel design stress allowables in creep and rupture test ranges than C 800H.

Applications

• Chemical and Petrochemical – piping, tubing, pigtails and outlet manifolds in steam/hydrocarbon reforming; tubing for ethylene production; tubing and heaters for oxo-alcohol production; hydrodealkylation units; tubing, flanges and bends for production of vinyl chloride monomer.
• Thermal Processing – tubing, muffles, retorts and fixtures in heat treating furnaces.
• Power Generation – tubing in power plant superheaters and reheaters.

Information provided by Carlson