Oxidation of Metals

, Volume 31, Issue 5–6, pp 453–478 | Cite as

High-temperature sulfidation of Mo-50 Wt.% Re

  • Ge Wang
  • F. Gesmundo
  • D. L. Douglass
Article

Abstract

Mo-50Re was sulfidized over the range of 1000–1100°C in sulfur vapor at pressures of 10−4 and 10−2 atm. The reaction kinetics followed the parabolic rate law with an activation energy of 55.4 kcal/mole for\(p_{S_2 } = 10^{ - 4} \) and 48.2 kcal/mole for\(p_{S_2 } = 10^{ - 2} \) atm. The pressure dependence varied between +1/4 to +1/6 for the slope of a plot of log Kp vs log\(p_{S_2 } \).

Analysis of the diffusional processes occurring in both the scale and the alloy substrate gave an expression for the ratio of the thickness of the scale and of the χ-phase as a function of the corresponding rate constants for the growth of each layer. Finally, the conditions required for the formation of the χ-phase layer between the outer scale and the alloy substrate were obtained in terms of the ratio between the diffusion coefficients of the two metals in the intermetallic compound.

Key words

Mo-50Re sulfidation x-phase MoS2 sulfur interstitials 

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Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • Ge Wang
    • 1
  • F. Gesmundo
    • 2
  • D. L. Douglass
    • 1
  1. 1.Department of Materials Science and EngineeringUniversity of CaliforniaLos Angeles
  2. 2.Istituto di Chimica per L'Ingegneria, Facolta di IngegneriaUniversita di GenovaGenovaItaly

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