Effect of a surface roughness on the erosion kinetics of Ba35 brass used in potable water pipelines: Experiments and mathematical modeling

Abstract The purpose of this work is to establish the relationship between surface roughness and erosion processes of Ba35brass pipes subjected to abrasive particles. Brass samples were prepared with different levels of surface roughness, obtained by polishing using abrasive papers of various grain sizes: P80, P120, and P320. These samples were eroded using a recirculating erosion test bench. To analyze the erosion kinetics, the surface roughness values (Ra and Rz) as well as the cumulative mass loss were measured at specified time intervals. In parallel, mathematical models were developed to simulate the evolution of surface roughness and cumulative mass loss, based on optimization methods. The results show that rougher surfaces, such as those prepared with P80 grit paper, record a higher erosion rate, reaching 0.47 mg/h, compared to smoother surfaces, such as those obtained with P320 paper, whose rate is 0.19 mg/h. The developed mathematical models indicate that the surface roughness follows an exponential decrease, while the cumulative mass loss shows a logarithmic growth. Furthermore, a linear correlation was highlighted between the erosion rate and the surface roughness. This study highlights the crucial importance of surface roughness in erosion processes and provides guidelines for optimizing the design and maintenance of cast iron pipes.