High-temperature oxidation behavior of low sulfur martensitic stainless steel 1Cr13Mo containing cerium

Abstract

The effect of cerium on the high-temperature oxidation behavior of low sulfur martensitic stainless steel 1Cr13Mo was investigated at 700°C, 800°C and 900°C in air, and then analyzed by means of X-ray diffraction, energy dispersive X-ray spectroscopy and electron probe microanalysis. The external scales formed on samples are composed of Cr2O3 and MnCr2O4 at 700°C and 800°C. When at 900°C, only M2O3 type oxide can be found in the scale of the sample without cerium, and there is still some MnCr2O4 that can be detected in the scale of the sample containing cerium, showing cerium benefits forming MnCr2O4 which makes the scale more protective. After oxidation at 900°C, in the sample containing cerium, segregation of cerium and chromium is found near the metal/scale interface, which indicates that cerium reduces the oxidation rate by modifying the transport process, changing the transportation mechanism from Cr3+ ions' outward diffusion into O2− anions' inward diffusion. Meanwhile, the sample containing cerium shows a smaller number of pores and lower sulfur content near the interface compared with the sample without cerium, which suggests that cerium reduces the pore formation and enhances the scale adhesion.