9Cr-1Mo鋼於乳化油燃燒氣氛之氯化鈉熱腐蝕

Hot Corrosion of 9Cr-1Mo Steel with NaCl Coating in an Atmosphere Produced by Burning Emulsified Diesel Oil

本研究以鉻鉬鋼（9Cr-1Mo）沈積2mg/cm2 NaCl，於750℃與850℃探討氯化鈉之熱腐蝕。實驗設備為燃燒爐，採用高級柴油及其含水10%之乳化油料為加原，探討合金於水蒸汽環境之腐蝕與形態。實驗結果顯示，9Cr-1Mo之金屬損失隨溫度之升高及氣氛含水蒸汽而增加，850℃之金屬損失比750℃大，且乳化油燃燒氣氛之金屬損失試驗結果比高柴燃燒氣氛大。此外，以乳化油為加熱源時，燃氣中含有較高之SO2，將導致材料遭受硫化腐蝕之情況比高柴燃燒氣氛嚴重，加速材料劣化。

The high-temperature corrosion of low alloy steel in a combustion furnace at 750℃ and 850℃was studied using 9Cr-1Mo alloy with 2 mg/cm2 NaCl coating. The atmosphere in this furnace was produced by burning ASTM 2D diesel oil or an emulsion thereof with 10% water. The experimental results indicate that both the higher temperature and the water vapor in the atmosphere promoted metal loss. The metal loss of 9Cr-1Mo alloy in the atmosphere that contained water vapor, resulting from the burning of emulsified oil, was larger than that obtained by burning just the diesel oil. Moreover, water vapor contributed to higher SO2 concentrations in the gas produced. Therefore, 9Cr-1Mo alloy suffers sulfidation more seriously in an atmosphere that contains water vapor than in one obtained by burning diesel oil; it thus deteriorates more rapidly.