材料期刊网

The corrosion behaviour of Fe-20Cr-5Al and Fe-20Cr-5Al-0.3Y in three aqueous solutions including 3.5 wt-% NaCl, 3.5 wt-% NaCl + 1.5 wt-% Na2S2O3 and 10 wt-% H2SO4 were investigated by electrochemical techniques. The results showed that Fe-20Cr-5Al-0.3Y exhibited better corrosion resistance than Fe-20Cr-5Al in NaCl solution. When Na2S2O3 was added in the NaCl solution, as expected, the two alloys suffered more serious localised corrosion, however, Fe-20Cr-5Al-0.3Y alloy exhibited better corrosion resistance than Fe-20Cr-5Al. Two alloys exhibited active-passive transition and trended toward general corrosion when tested in H2SO4 solution. The corrosion current densities for each alloy corroded in H2SO4 solution were higher than that corroded in NaCl and NaCl + Na2S2O3. Meanwhile, the addition of a small amount of Y in Fe-20Cr-5Al alloy increased the corrosion resistance of this alloy in H2SO4 solution. The corrosion mechanisms of two alloys and the effect of Y addition on the corrosion behaviour of Fe-20Cr-5Al are discussed.