Oxidation behaviors of 0Cr15Ni5Cu2Ti steel at high temperature

High temperature oxidation behaviors of 0Cr15Ni5Cu2Ti steel are studied at 500, 600, 700 and 800°C. The microstructures of the scales formed and the underlying alloy are characterized by scanning electron microscopy (SEM) and optical microscopy (OM). The chemical and oxide phases of the scales are investigated using energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively. The oxidation curves at 700°C or below follow the parabolic laws because of the formation of a protective Cr-rich layer. The oxidation behavior of the steel at 800°C is subject to a breakaway oxidation with fast growing of oxide nodules on the surface. The phase transformation from lath martensite to austenitic phase in the alloy below the scale may be one reason causing the formation of the nodules. The latter are very susceptible to spallation.