Abstract The article presents results of studies on the wear resistance of structural steels used to manufacture shafts for rotary positive‑displacement pumps. A characteristic feature of these pumps is the extremely small clearances between their working elements, on the order of about 10–25 µm, which depend on the amount of wear of the shafts at the bearing interfaces. Glow‑discharge nitriding (plasma nitriding) is the most efficient method for providing high wear resistance of parts. It is shown that one of the adverse phenomena during wear of the nitrided layer is the formation of abrasive particles as a result of spalling; these particles promote surface scoring of the bushing and, consequently, accelerate the wear process. The aim of the work was to investigate the wear resistance of steel that was glow‑discharge nitrided following preliminary processing by surface plastic deformation, medium‑energy ion implantation, magnetic‑pulse processing, and combined activation methods. The following surface activation regimes were used prior to ion nitriding: shot‑peening with steel microspheres 50–100 µm in diameter at speeds of 30–70 m/s; implanted ions—nitrogen; dose—1.3 × 1017 ions/cm2; dose rate—1 × 1015 ions/s; ion implantation energy – 25 keV. Magnetic‑pulse processing (MPP) was carried out with pulse energies from 2 to 8 kJ, pulse durations from 5 to 40 µs, and number of pulses from 2 to 5. It was shown that the most efficient preliminary surface‑activation method before nitriding is medium‑energy ion implantation, which allows increasing the wear resistance of the nitrided layer of 40Kh steel by a factor of 5.7 and of 40KhN steel by a factor of 4.5 compared with conventional ion nitriding.