| The sulfidation behaviors of pure Cu, Cu Mn and Cu Ni alloys were studied in sulfur vapor atmosphere over the temperature range of 300 to 600℃. The sulfidation rates of copper were decreased significantly with increasing Mn or Ni content of the alloys, and activation energy for pure Cu was almost same with values of Cu Mn and Cu Ni alloys. Scales for the alloys always consisted of two layers, an outer layer and an inner complex layer. The outer layer always was only copper sulfides. Cu S and Cu S₄, on the other hand the inner layer which exhibited the porous structure contained two sulfides, such as nickel sulfides or manganese sulfides as well as copper sulfides. In the case of pure Cu, platinum marker was found near to the metal surface. However, for Cu Mn and Cu Ni alloys markers were found near to the interface of the inner and outer scales. From those results, the predominent defects in sulfidation and the reaction mechanisms were explained, accordingly. |
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