Accession Number : ADA192141

Title :   Calculations of the Gaseous Species in Halide Activated Cementation Packs.

Descriptive Note : Technical rept.,

Corporate Author : OHIO STATE UNIV RESEARCH FOUNDATION COLUMBUS

Personal Author(s) : Kung, S C ; Rapp, Robert A

PDF Url : ADA192141

Report Date : Feb 1988

Pagination or Media Count : 38

Abstract : The equilibrium partial pressures of gaseous species in cementation packs using pure condensed aluminum (1), chromium (s), and silicon (s) metals, activated by various halide salts under argon or reducing environments containing different amounts of hydrogen, have been calculated. The analyses indicate that the presence of hydrogen gas in the system does not significantly alter the equilibrium partial pressures of gaseous species for a pack containing Al at unit activity. However in the absence of aluminum, the vapor pressures of chromium - and silicon-halides are maximized in a hydrogen-free inert gas environment. The vapor pressures for the volatile chlorides of iron are significantly higher than those for nickel or cobalt, so that displacement reactions leading to the loss of fe from the substrate are expected for coating processes involving higher halide activities, e.g,, chromizing or siliconizing.

Descriptors :   *ALUMINUM, *CHROMIUM, *HALIDES, *HEAT RESISTANT ALLOYS, *ACTIVATION, *BINARY ALLOYS, ARGON, CHLORIDES, CHROMIZING, COATINGS, COBALT, DISPLACEMENT REACTIONS, ENVIRONMENTS, EQUILIBRIUM(GENERAL), GASES, HYDROGEN, IRON, NICKEL, PARTIAL PRESSURE, SALTS, SILICON, VAPOR PRESSURE, IRON, DIFFUSION COATINGS, POWDER METALS

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE