不同氣體流率對鐵–鉬兩元合金於H2/H2O/H2S混合氣氛之高溫腐蝕影響

The Effects of Different Flow Rates on the High-Temperature Corrosion of Fe-Mo Binary Alloys in H2/H2O/H2S Atmospheres

本研究主要探討不同氣體流量對鐵-鉬兩元合金於H2/H2O/H2S混合氣氛之高溫腐蝕；其結果歸納為：(1)在不同氣體流率下，合金的腐蝕物都形成雙層硫化物，惟高氣體流率下，腐蝕的內、外層厚度明顯地增厚，而腐蝕的動力學反應都遵守拋物線型定律，(2)在高氣體流率下的腐蝕速率也較快，其差異性會隨著腐蝕溫度的提高及含鉬量的降低而趨明顯，(3)由白金指標位於內、外層硫化物之間的結果顯示，合金的腐蝕反應機構在不同氣體流率下並未改變。

The effects of different flow rates on the high-temperature corrosion of Fe-Mo binary alloys were studied in H2/H2O/H2S atmospheres. The scales formed on Fe-Mo alloys at the higher flow rate (150 c.c./min.) were nearly identical to those at the slower flow rate (20 c.c./min.), however, both the inner and outer scales were significantly thicker. The reaction kinetics followed the parabolic rate law, regardless of different temperatures and flow rates. The corrosion rates of the alloys measured at higher flow rate were much higher than those at slower flow rate, and more pronounced effect occurred for the alloys with smaller Mo additions at higher temperatures (≧ 800℃). Platinum markers were always located at the interface between the inner and outer scales, indicating that the reaction mechanism to form the duplex scale was the same at both flow rates.