René 80超合金在600-800℃之H2/H2S及H2/H2S/H2O混合氣氛下的高溫腐蝕行為

High-temperature Corrosion of Rene 80 Superalloy in H2/H2S and H2/H2S/H2O Gas Mixtures at 600-800℃

本文探討鎳基超合金René 80於600-800℃之H2/H2S及H2/H2S/H2O混合氣之腐蝕行為，研究結果顯示René 80之高溫硫化皆遵守拋物線型定律，硫化速率隨溫度之上升而加快，且H2/H2S混合氣氛之腐蝕速率與H2/H2S/H2O混合氣氛下腐蝕速率相差不大。René 80在兩種不同氣氛下腐蝕後皆生成內、外兩層的腐蝕物，包括外層的硫化鎳（Ni3S2）及少量的硫化鈷（Co9S8/Co6S5），內層主要為硫化鉻（Cr2S3/Cr3S4）、硫化鎳鉻（NiCr2S4）、硫化鈷鉻（CoCr2S4）、硫化鎳（Ni3S2），由白金指標實驗得知，白金位置皆位於腐蝕物內、外層之間，可知外層主要是因為陽離子向外擴散所致，而內層則主要是陰離子往內擴散的結果。

The high-temperature corrosion behavior of Rene 80 Superalloy was studied over the temperature range 600-800℃ in H2/H2S and H2/H2S/H2O gas mixtures. In general, the corrosion kinetics followed the parabolic rate law, the corrosion rate constants increased with increasing temperature. The scales formed on Rene 80 were duplex, consisting of an outer layer of Ni3S2 and some Co9S8/Co6S5, and an inner layer of mostly Cr2S3/Cr3S4, some NiCr2S4, CoCr2S4, and Ni3S2. The position of Pt-marker was always located at the inner- and outer-layer boundary, suggesting that the outer layer grew by outward diffusion of cations and the inner layer formed by means of inward diffusion of sulfur.