The Effects of Composition and Microstructure Variation on the Oxidation Characteristics of Stainless Steels Manufactured by Powder Metallurgy Method

As well-known wrought stainless steel, sintered stainless steel (STS) has excellent high-temperature anti-corrosion even at high temperature of , and exhibits good corrosion resistance in air. However, when temperature increases above , the corrosion resistance of STS begins to deteriorate and dramatically decreases. In this study, the effects of phase and composition of STS on high-temperature corrosion resistances are investigated for STS 316L, STS 304 and STS 434L above . The morphology of the oxide layers are observed. The oxides phase and composition are identified using X-ray diffractometer and energy dispersive spectroscopy. The results demonstrate that the best corrosion resistance of STS could be improved to that of 434L. The poor corrosion resistance of the austenitic stainless steels is due to the fact that oxides forming poor adhesion between the matrix and oxide film increase the oxidation susceptibility of the material at high temperature.