The High Temperature Oxidation Stability of STS434L/Silicon Oxide Compacts

In order to improve the high-temperature oxidation stability, a study of 434L sintered stainless steel was focused on the effect of addition of metallic oxides to form stable oxide film on the inner particle surface. In this paper, oxidation behavior of 434L compacted parts in accordance with the addition of metallic oxides were discussed with high temperature oxidative reaction, and sintering behavior analysis under 950°C. Oxidation weight gains of 434 L have increased as a form of parabolic laws. The hightemperature oxidation resistance was improved by the mixed addition of amorphous SiO₂ and silica up to 2wt.%. The oxidation rate was decreased and kept constant after 60 hours. It was caused by the restraint succeeding oxidation due to the stable oxide formation of Cr₂SiO₄ phases on the particle surface to prevent densification and inhibition the external diffusion of Cr. High-temperature stability was confirmed by the electrical resistivity maintains the constant value of 1.3×10^-2 Ω ·cm when the silica added less than 2w/o to 1w/o A-SiO₂ added 434L.