In this study, agglomerated TiO2 and TiO2 nanopowders with Cr2O3 addition were tested for erosive wear in a slurry environment. Their abrasiveness, mass loss, and volume loss were investigated. The slag slurry was sieved to an average particle size of 450–515 μm, and media containing 10 wt% slag were prepared. Experiments were conducted at particle velocities of 2 m/s and 4 m/s with normal impact angles (90°). The results revealed that TiO2+Cr2O3 nanocoatings exhibited approximately 25% higher resistance to erosive wear compared to pure TiO2 coatings. Moreover, wear increased with rotational speed, highlighting the influence of mechanical conditions on coating performance. Overall, the addition of Cr2O3 significantly enhanced the mechanical stability and durability of the coatings. These findings provide important insights into the wear mechanisms of nanopowder-based coatings and demonstrate the potential of TiO2+Cr2O3 systems for improving the performance and service life of components operating under high-wear conditions, particularly in industries involving abrasive slurry flows and particulate impact, such as mining, energy, and chemical processing.