Abstract
The oxidation behaviors of three kinds of 80Ni-20Cr alloy containing 0.1 and 0.01%Be and without Be, respectively, were studied over the temperature range of 900°∼1200°C in the atmosphere. Oxidation tests were carried out by the repeated heating method and also by the continuous heating method. The oxidation products on these alloys were observed by means of metallography, X-ray diffraction, electron diffraction and electron probe microanalysis.
It has been shown that the addition of 0.1%Be is effective to prevention of the high temperature oxidation below 1100°C. It decreases the oxidation rate and prevents the spalling of the protective oxide scale during the heating and cooling cycle. The 0.1%Be alloy forms a dense, uniform oxide layer that is composed mainly of Cr2O3 and also a subscale that penetrated along the grain boundaries of alloy into the matrix from the oxide layer.
