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研究了Ｆｅ－２０Ｃｒ－５Ａｌ和Ｆｅ－２０ＣｒＳＡｌ－０．５Ｙ合金在１２００℃ｌａｔｍＳＯ２气氛中热循环条件下的高温腐蚀行为，并与恒温腐蚀相比较．测定了腐蚀动力学曲线，观察腐蚀产物表面，横截面和脆断断口的形貌，并分析元素的分布，确定腐蚀产物相组成．结果表明，在５０００小时实验周期内，不含钇的合金遭受氧化／硫化腐蚀，腐蚀动力学呈直线规律．含钇合金只发生高温氧化反应，腐蚀动力学与恒温腐蚀时的差别不大，仍大体符合抛物线规律．加钇有效地抑制了Ａｌ３＋在α－Ａｌ２Ｏ３中的扩散，合金表面氧化膜依赖氧的传质而成长，发展出粘着性好的柱状晶，在交变热应力作用下不易开裂和剥落，显著提高了合金的耐蚀性．
The high temperature corrosion behavior of Fe-20Cr-5Al and Fe-20CrSAl-0.5Y alloys under 1200 ℃ latmSO2 thermal cycling was investigated and compared with that of constant temperature corrosion. The corrosion kinetics curves were measured and the morphology of corrosion products surface, cross section and brittle fracture were observed. The distribution of elements was analyzed to determine the phase composition of corrosion products. The results show that the alloy containing no yttrium undergoes oxidation / sulfidation corrosion during 5000 hours experimental period, and the corrosion kinetics shows a linear rule. Containing yttrium alloy only high temperature oxidation reaction, corrosion kinetics and constant temperature corrosion is not very different, still generally in line with the law of parabola. The addition of yttrium effectively inhibits the diffusion of Al3 + in α-Al2O3. The oxide film on the surface of the alloy grows on the basis of oxygen mass transfer and develops well-adhered columnar crystals, which are not easy to crack and peel under the action of alternating thermal stress and markedly improved The corrosion resistance of the alloy.