High Temperature Oxidation Studies on Alloys Containing Dispersed Phase Particles and Clarification of the Mechanism of Growth of SiO2

摘要

In most binary transition metal alloys, additions of Cr are used to promote the formation of a protective Cr2O3 layer. Once formed, this layer acts as a barrier between the metal and its environment and, thereby, prolongs service life of the alloy. The ability to form such a layer depends upon a complex interaction of variables; the most influential being the concentration of Cr present in the alloy. In fact, there is a critical concentration of Cr, below which a complete, protective CR2O3 scale will not form. Under the severe conditions employed in this investigation, upwards of 18 weight percent Cr is required to form a protective layer in the binary Ni-Cr and Fe-Cr alloys. (JES)