WEAR OF THE SURFACES OF PARTS OF OIL-FIELD EQUIPMENT OPERATING IN AN ABRASIVE MEDIUM

Abstract

The results of numerous studies show that surfaces treated by different methods deviate from the specified shape and degree of roughness, regardless of the manufacturing technology employed. These errors have a significant effect on the wear of the contact surfaces of parts that comprise friction couples. Thus, they also have a significant effect on the durability of machines in general. The actual area of contact of surfaces depends mainly on their microscopic and macroscopic geometry and the loads applied to them. To a large extent, the wear that the surfaces of parts undergo is caused by the cutting of microscop ic scallop-shaped projections that remain on the surface after the treatment. The quantitative values obtained to characterize wear are a reflection of a volumetric change in the surfaces of parts. The results of the studies in [1] show that metallic su rfaces have roughness at the atomic level and that their highest protuberances are the parts of the roughness that make contact with other surfaces. For metals in air at room temperature, those protuberances may be dust particles. Dust particles can take up most or all of the loads on the surface when those loads are small. An examination of parts that had been machined established that small particles of the material of the tool are almost