Erosion of 38CrMoAlA Drilling Tool Steel in Slurry: Effect of Particle Concentration on Downhole Tool Clearance Material

Understanding slurry erosion characteristics in a fit clearance structure is vitally important for improving the service life of downhole tools. In this study, erosion test equipment was designed to simulate the flow of high-speed drilling fluid in a clearance, and its performance was tested by studying the concentration effect of solid particles on the erosion behavior of a commonly used 38CrMoAlA steel material in downhole tools. The experimental results revealed that localized erosion occurred on the clearance internal surface along the flow channel direction. An area a certain distance from the slurry entry was most severely eroded. Moreover, the erosion rate, erosive wear depth, and surface hardness increased while the roughness of the eroded surface decreased with increasing particle concentration. To extend the service life of downhole tools, the concentration of solid particles should be controlled, and the localized erosive area should be prioritized.