EFFECT OF COMPRESSIVE LOADS ON THE OXIDE-SCALE MORPHOLOGY FORMED ON Ni-12Cr ALLOY AT 1173K

摘要

The effect of a compressive load on the scale morphology was studied by comparison of the oxidation behavior of Ni-12Cr in air under compressive load and without any applied load at the temperature of 1173K. This study was performed mainly by comparisons of surface micrographs observed by scanning electronic microscopy (SEM). The surface oxide was examined by X-ray diffraction (XRD). It is found that the oxide scales developed wedge-type cracks before spalling when subjected to a load, and the wedge-type cracks grew with increasing time, which is related to the oxide-scale failure for the samples subjected to oxidation under a compressive load. Furthermore, the applying load induced a Cr_2O_3 layer to form on the Ni-12Cr alloy.