The Effects of Small Amounts of Niobium Addition to Mechanical Alloyed AISI 304 Stainless Steel on the Microstructural and Tribological Properties

In this study, the effects of different amounts (max 1%) of niobium added to mechanical alloyed AISI 304 austenitic stainless steel on the hardness, density, microstructure, and wear behavior were investigated. After the AISI 304/Nb alloy powders were cold pressed, they were sintered in vacuum environment (10(-6) mbar) at 1300 degrees C. The produced AISI 304/Nb samples were characterized by scanning electron microscopy, X-ray diffraction, and hardness and density measurements. Wear tests were performed under dry friction at room temperature using a pin-on-disk wear device. Result of the study showed that the addition of niobium up to 0.4% increased the hardness of the alloy and improved wear behavior while greater ratios reduced the hardness of the alloy and negatively affected wear behavior. Oxidation occurred on the worn surface and lines were formed in the sliding direction. In addition, as the hardness values of the alloy increased, weight loss decreased.