銅基合金在500-800℃下之高溫硫化行為研究

High-Temperature Sulfidation Behavior of Cu-Base Alloys

本研究探討二種商用銅基合金（含Cu-25Zn及Cu-25Zn-5Al，皆為at%）在500 ~ 800℃之H2/H2S混合氣氛的腐蝕行為。結果顯示，銅基合金的腐蝕動力學皆遵守拋物線型定律，而其腐蝕速率隨著溫度的增加而增加。總體而言，Cu-25Zn-5Al的抗硫化性質較Cu-25Zn好。銅基合金在混合氣氛之腐蝕生成物，大致上可分為內、外兩層腐蝕層，其中，Cu-25Zn外層主要生成硫化亞銅（Cu2S），內層主要為硫化鋅（ZnS）；而Cu-25Zn-5Al外層主要生成硫化亞銅（Cu2S），內層主要為硫化鋅（ZnS）及少量的硫化銅鋁（CuAlS2）。

High-temperature sulfidation behavior of two Cu-base alloys (containing Cu-25Zn and Cu-25Zn-5Al, in at%) over the temperature range 500 ~ 800℃ in H2/H2S gas mixtures was studied. In gerneral, the sulfidation kinetics of both alloys followed the parabolic rate law at all temperatures, and the corrosion rate constants increased with increasing temperature. The sulfidation resistance of the ternary alloy is much better than the binary alloy. The scales formed in H2/H2S gas mixtures were complex and heterophasic, consisting of an outer layer of Cu2S and an inner layer of ZnS for Cu-25Zn, and of an outer layer of Cu2S and an inner layer of mostly ZnS and minor CuAlS2 for Cu-25Zn-5Al.