Deformation of oxide scales on Fe‐20Cr alloy under compressive stress

Abstract

The behavior of oxide scales on Fe‐20Cr alloy was investigated in constant load at 1173 K in air. The objective was to understand the effect of mechanical loading on the deformation of oxide scales. It was carried out mainly by comparison of surface morphologies of oxidized specimens observed by scanning electronic microscope (SEM). In all cases, the oxide scales formed on specimens without stress showed a flat surface. However, oxide scales formed on specimens after 20 h of oxidation under a stress of 8 MPa (strain 3.07%) showed slip band characteristics. Furthermore, for longer oxidation time up to 65 h, slip bands formed under a low stress of 2 MPa (strain 1.19%), and grain boundary sliding became the main surface feature for the specimens subjected to a stress of 5 MPa (strain 2.53%). Two typical deformation forms are illustrated in the work.