A new method of plasma electrolytic chemical-thermal treatment by the directed action of an electrolyte jet on the surface being treated is proposed. Using the example of treating a rotating axisymmetric workpiece, the thermophysical features of the process, changes in the structural-phase composition of the surface layer, surface morphology and tribological properties in the contact area of the electrolyte jet with the surface being treated and adjacent areas of low-carbon steel are studied. The formation of a gradient of structural-phase changes is shown, which is determined by a change in temperature and intensity of carbon diffusion, as well as the cooling rate during quenching. Depending on the specified conditions, a change in the structure is observed from martensitic with a microhardness of up to 980 HV at a high heating temperature and cooling rate to quasi-eutectoid with a reduced microhardness (280–320 HV). The competing effect of high-temperature oxidation and anodic dissolution on the surface morphology and its roughness. The tribological efficiency of jet treatment is revealed, caused by the work of oxide layers as a lubricant in combination with a high-hardness matrix and an increase in the bearing capacity of the surface profile after processing. The presented processing method allows to reduce the friction coefficient by 1.4–1.6 times, weight wear by more than 60 times, and volume wear by 10–27 times in the contact zone of the electrolyte jet with the surface.