Calculations of the Gaseous Species in Halide Activated Cementation Packs.

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.

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Document Details

Document Type
Technical Report
Publication Date
Feb 01, 1988
Accession Number
ADA192141

Entities

People

  • Robert A. Rapp
  • S. C. Kung

Organizations

  • Ohio State University

Tags

Communities of Interest

  • Advanced Electronics

DTIC Thesaurus Topics

  • Alloys
  • Chemical Reactions
  • Coatings
  • Computer Programs
  • Corrosion Resistance
  • Displacement Reactions
  • Elements
  • Energy
  • Engineering
  • Materials
  • Pack Cementation
  • Partial Pressure
  • Standards
  • Surface Reactions
  • Thermodynamic Properties
  • Thermodynamics
  • Vapor Pressure

Readers

  • Electrochemical Engineering/ Fuel Cell Technologies
  • Surface Engineering/Surface Coating Technology.