Abstract: The abrasion characteristics of 16Mn steel elbows transporting paste containing coarse aggregate were investigated by employing contact stress and indentation depth as wear indicators. Based on Hertzian contact theory, quantitative relationships were established relating contact stress and indentation depth to coarse aggregate radius, sliding velocity, and elbow curvature radius. Grey relational analysis and the SHAP interpretability method were employed to quantify the contribution of each factor to elbow wear. Results indicate that both contact stress and indentation depth increase with aggregate radius and sliding velocity following a power-law function, while a decreasing trend was found with increasing elbow radius. Among the investigated factors, aggregate sliding velocity was identified as the most significant influence on wear, followed by aggregate radius and elbow radius. Under extremely unfavorable conditions, a maximum contact stress of 105.9 MPa was calculated, accounting for only 30.7% of the yield strength of 16Mn steel. Consequently, fatigue crack initiation and thin-layer spallation were determined to be the dominant wear mechanisms. These findings provide theoretical guidance for wear mitigation strategies in pipe elbows conveying paste backfill.