Co-Al兩元合金在H2/H2S/H2O混合氣氛下之高溫腐蝕行為

High-temperature Corrosion of Co-Al Binary Alloys in H2/H2S/H2O Gas Mixture

本研究主要探討Co-Al合金（含Co-0、2、5、10wt.%Al）在600-800℃之H2/H2S/H2O混合氣氛之高溫腐蝕行為。研究結果顯示，Co-Al合金之腐蝕動力學皆遵守拋物線型定律，且腐蝕速率隨Al含量之增加而降低，但Co-5Al與Co-10Al在700℃～ 800℃間有動力學逆轉現象；Co-Al合金腐蝕後，其結果發現生成內、外兩層的腐蝕物，包括外層的硫化鈷（Co9S8）及內層為複雜的硫化鋁（Al2S3）、氧化鋁（Al2O3）及少量的硫化鈷（Co9S8）。

The high-temperature corrosion behavior of Co-Al binary alloys (containing Co-2, 5, and 10wt.% Al) was studied over the temperature range 600-800℃ in H2/H2S/H2O gas mixture. Generally, the corrosion kinetics of all the alloys followed the parabolic rate law, and the corrosion rate decreased with increasing Al content. The kinetics inversion was observed between 700 and 800℃ for higher Al alloys (>5%Al). The scales formed on the alloys were duplex, consisting of an outer-layer of Co9S8 and of an inner-layer of mostly Al2S3, Al2O3, and minor amounts of Co9S8.