Wear law of Q345 steel under the abrasion–corrosion synergistic effect of cemented paste backfill

Abstract

Excessive pipe wear affects the continuity and safety of the delivery of cemented paste backfill (CPB). However, the dominant factors affecting the wear of CPB transportation pipelines are not well understood. The goal of this study is to determine the wear law of the Q345 steel pipeline under the abrasion–corrosion synergistic effect of CPB at varying mass fractions (76–82%), flow velocities (1–2.5 m/s), and rheological parameters. A mini cathodic protection system was installed in the slurry pot tester to simultaneously acquire the total wear and pure abrasion, while pure corrosion was obtained via immersion testing. The results indicate that the total wear and pure abrasion exhibit a power-law increase according to flow velocity and grow exponentially as the CPB mass fraction increases. CPB with increasing yield stress and plastic viscosity leads to an exponential growth in the total wear and pure abrasion. However, a higher solid fraction not exceeding a certain critical value effectively alleviates pipe wear and resistance. In most cases, the synergistic effect of abrasion–corrosion contributed to more than 50% of the total wear. CPB mass fraction and the abrasion-corrosion synergistic effect are the dominant factors affecting the total wear of the CPB-transporting pipeline and should be properly controlled in practice. CPB with a solid fraction ranging between 76 and 78% at a flow velocity of 1.57 m/s and pipelines made of corrosion-resistant materials are recommended for the mine of interest. The findings are conducive to the selection of appropriate pipeline materials and CPB transportation parameters.