This study investigated parametrically the erosive wear behavior of AISI 1015 and 304 steel in different environmental conditions. The erosive wear tests were designed according to the L9 orthogonal array design of the Taguchi fractional factorial method. The experiments were carried out with the parameters of 3-level slurry concentration formed with silica powder (5, 15, and 25 wt.%), 3-level impact velocity (265, 397.5, and 530 rpm), and 3-level impact angle (30°, 60°, and 90°). Surface roughness and weight loss were considered performance criteria in the experimental data assessed using the signal/noise (S/N) and analysis of variance (ANOVA) methodologies. In addition, the wear zones of the samples were examined in detail with SEM, EDX, and 3D topography analyses. According to the S/N analysis, the best wear and surface roughness parameters for AISI 1015 and 304 steel were determined as 5% by weight concentration ratio, 265 rpm for impact speed, and 90° for impact angle. It was determined that low concentration, low speed, and high impact angle values affected surface roughness and weight loss parameters positively. Experimental results showed that erosive wear resistance increased with the increasing alloying elements in steel materials.