INFLUENCE OF THE CHEMICAL-COMPOSITION AND THE FABRICATION PROCESS ON THE BEHAVIOR OF HIGH-TEMPERATURE OXIDATION OF FE-CR-AL ALLOYS

The oxidation behaviour of four industrial Fe-Cr-Al alloys was studied . Two of them were Fe-Cr-Al alloys fabricated either by melting or by powder metallurgy. The two other ones were Fe-Cr-Al-Y alloys either pr oduced by melting or by mechanical alloying. On these alloys, we deter mined oxidation kinetics and observed the morphology of the oxide laye r after isothermal and cyclic exposures from 1000 degrees C up to 1300 degrees C. The beneficial effect of yttrium on the adherence of oxide layers was confirmed. The powder metallurgy fabrication route does no t improve the oxidation resistance of yttrium-free alloys. On the othe r hand, the association of the powder metallurgy and the addition of y ttrium allow the manufacturing of alloys which present an excellent be haviour to high temperature oxidation.