TECHNOLOGY FOR RESTORATION AND SURFACE HARDENING OF PLUNGER PAIRS IN HIGH-PRESSURE FUEL PUMPS

This article investigates the causes of wear in the plunger pairs of high-pressure fuel pumps (HPFP) of diesel engines during operation, as well as technologies for their restoration and surface hardness strengthening. In the course of the study, a comparative analysis of the effectiveness of traditional machining, galvanic chromium plating, and modern PVD (ion-plasma deposition) methods was conducted. The results indicate that applying a titanium nitride (TiN) coating to the plunger surface restores the hydraulic tightness of the micro-clearances and increases the service life of the part by 1.8–2.0 times. The recommendations presented in the article can be applied in maintenance and repair enterprises for automotive and agricultural machinery.