CYCLIC OXIDATION BEHAVIOR OF 800 SERIES CHROMIA-FORMING ALLOYS

摘要

The cyclic oxidation behavior of four commercial iron-base 800 series chromia-forming alloys was studied at 1000 deg C in still air. Each thermal cycle consisted of one day at temperature followed by air- cooling to room temperature. Two different types of alloys were studied (800 and 800HT), with the alloys being supplied by two different producers. Although the alloys were of similar chemical composition, their variations in microstructure and minor constituent contents were apparently sufficiently different to cause marked differences in oxidation behavior. The 800HT alloys generally performed the worst, undergoing rapid weight-loss kinetics after a period of relatively protective oxidation. The time required for the commencement of rapid weight-loss kinetics depended significantly on the producer of the 800HT alloy. The oxidation behavior of the 800 alloys was also producer dependent, but not to the significant extent found for the 800HT alloys.