Observation of phase transformation and grain growth phenomena in aluminised Super 304H during steam oxidation
Electron backscattered diffraction (EBSD) maps acquired in the diffusion zone of aluminised Super 304H steel samples showed that a phase change and associated grain growth phenomena had occurred during high temperature aging in flowing steam environments. This phase transformation could have a significant influence on reducing the oxidation resistance and mechanical stability of the aluminised layer at high temperatures. Scanning electron microscopy combined with energy dispersive X-ray spectroscopy and EBSD mapping provides a valuable insight into microstructural changes occurring in coated alloy systems during high temperature aging processes.