Effects of yttrium on the oxidation behaviour of Iron‐Chromium‐Aluminium Alloys

The effects of yttrium additions on the oxidation behaviour of Fe‐20Cr‐5Al(wt%) alloys have been investigated in oxidation tests and cyclic heating‐element tests at temperatures ranging from 1100 to 1400°C in air. Experimental results showed that the oxidation resistance of the alloys depends sensitively on the yttrium concentration. It was found that yttrium additions of about 0.045 wt% are sufficient to prevent the oxide scale from spalling. When the yttrium content is increased to more than 0.08 wt%, on the other hand, substantial internal oxidation of the alloys takes place, resulting in rapid wastage of the materials.