摘要
研究表面分別有混合盐Na_2SO_4-NaCl,Na_2SO_4-V_2O_5和纯Na_2SO_4沉积并在模拟燃气气氛中Fe_3Al和FeAl于600℃的热腐蚀,在所有试验条件下两种合金均发生热腐蚀。随试验时间的延长、纯Na_2SO_4和Na_2SO_4-NaCI引起的腐蚀明显减缓,而Na_2SO_4-V_2O_5的腐蚀则加剧并长时持续。FeAl一般较之Fe_3AI耐蚀,只有在Na_2SO_4-NaCl情况下两者腐蚀性能相近。所有合金的腐蚀产物层总是由一高铁的外层和含铝与铁和少量硫的内层组成,后者的成分随所涂盐的组成而变化。在一定程度上腐蚀机制涉及氧化-硫化与氧化物的熔融等。
It is demostrated that hot corrosion of two Fe-Al intermetallics Fe_3Al and FeAl may be induced by salts Na_2SO_4, Na_2SO_4+NaCl and Na_2SO_4+V_2O_5 in a simulated combustion gas atmosphere N_2+1.0% O_2+0.5% SO_2 at 600℃. However, the corrosion induced by pure Na_2SO_4 or Na_2SO_4+NaCl slows down after an initial period, while the corrosion induced by Na_2SO_4+V_2O_5 is more severe and long lasting. Except for the case of Na_2SO_4+NaCI, Fe_3Al is corroded heavier than FeAl. The corrosion products tor the alloys show two main zones, the outer of which contains mostly iron oxide, while the inner zone is a mixture of Al oxide and sulfide with some Fe and S, whose composition differs for the two salts mixtures. The corrosion mechanism is then discussed in terms of oxidation-sulfidation and scale fluxing models.
出处
《腐蚀科学与防护技术》
CAS
CSCD
1993年第1期52-58,共7页
Corrosion Science and Protection Technology
