High-temperature Oxidation of Hot-dip Aluminized 2.25Cr-1Mo Steel

摘要

When 2.25Cr-1Mo steel was hot-dip aluminized, a coating consisting of (Al-rich topcoat)/(Al13Fe4 layer)/(Al5Fe2 layer) formed. With increment of oxidation temperature, the transform of Al - Al13Fe4 - Al5Fe2 - AlFe - AlFe3 -alpha-Fe(Al)-alpha-Fe occurred through interdiffusion between the coating and the substrate as follows. The oxidation at 700 degrees C changed the coating to (alpha-Al2O3 scale)/(alpha-Al2O3, Al13Fe4, Al5Fe2)-mixed layer)/(Al5Fe2 layer)/(AIFe layer)/(AlFe3 layer)/(alpha-Fe(All layer). The oxidation at 800 degrees C changed the coating to (alpha-Al2O3 scale)/((alpha-Al2O3, Al5Fe2)-mixed layer)/(Al5Fe2 layer)/(AlFe layer)/(AlFe3 layer)/(alpha-Fe(Al) layer). The oxidation at 900 degrees C changed the coating to (alpha -Al2O3 scale)/((alpha-Al2O3, AlFe)-mixed layer)/(AIFe layer)/(AlFe3 layer)/(alpha-Fe(Al) layer). The oxidation at 1000 degrees C changed the coating to ((alpha-Al2O3, Fe2O3)-mixed layer))/(AlFe3 layer)/(alpha-Fe(Al) layer).