Abstract
Copper plates were exposed in sulfur containing atmosphere made by sodium sulfide solutions for up to 180 days. The cathodic reduction method was used to execute the qualitative analysis of the film formed on copper plate. The thickness and constituents of the film have been investigated by cross-sectional observation and EPMA analysis. Cathodic reduction curves revealed that the film was mainly composed of CuO, Cu2O and Cu2S. The thickness of the film formed in sulfur containing atmosphere made by 1 wt%Na2S solution has increased with an increase in an exposure period and reached about 40μm for 180 days. Multilayered film composed of sulfide and oxide was identified by the EPMA analysis.