Analysis of the oxidation process of powders and sinters of the austenitic stainless steel

Nowadays, austenitic stainless steels due to its properties are widely used in various applications. In powder metallurgy technology, one of the key factors, affecting the pressing process, the sintering phenomena and the final properties of sintered parts, is the shape and particle size of the powders. The article presents the results focused on analysis of the oxidation process of austenitic stainless steel. Powders of the same chemical composition, however of different shapes, depending on the manufacturing technique, i.e. spherical after inert gas atomization and sponge after water atomization, were investigated. Moreover, the influence of particles’ size from different ranges 40–56 and 80–100 µm on the oxidation behaviour was analysed. Thermal measurements, differential scanning calorimetry and thermogravimetry, were performed by the STA 409 CD (Netzsch) advanced coupling techniques. Moreover, dilatometry technique has been used for the analysis of the influence of the size and shape of particles on the sintering process. Sinters oxidation phenomena have also been determined. Based on the obtained results, it was found that both shape and size of powders have a significant influence on the oxidation processes of powders as well as sinters of the austenitic stainless steel.