Features of steel contact surface wear in sliding under low contact pressure

The С235 steel samples were dry-slid along the counterbody (C45 steel) according to the pin-on-ring configuration scheme (shaft-pad type) at sliding speeds of 0.75 – 8.0 m/s under a contact pressure of 0.13 MPa. The need for such an experiment is justified by the lack of indicative data on the tribotechnical behavior of steel in sliding contact with steel in the absence of oxidation products in the contact space. Temperature of the sample holder does not exceed 35 °C at all sliding speeds. This allows us to assume that there are no oxidation products on the contact surfaces. Formation of the transfer layer is visually observed in sliding only at low speeds: 0.75 – 1.3 m/s. The friction coefficient decreases during the formation time of the transfer layer and reaches a final value of about 0.4. The sliding surfaces of the samples contain signs of adhesive interaction at all sliding speeds. Adhesion is particularly pronounced on the sliding surface of the sample at a sliding speed of 2.5 m/s. The friction coefficient at this sliding speed has significant fluctuations around 0.8 ± 0.1. At the same time, there is a high rate of wear. Dependence of wear intensity on the sliding speed has maximum at a sliding speed of 2.5 m/s. The lowest wear rate is observed at a sliding speed of 5.0 m/s and at friction coefficient of about 0.7 ± 0.05. A low amplitude of friction coefficient fluctuations (0.7 ± 0.03) is observed when sliding at a speed of 8.0 m/s. X -ray phase analysis showed that contact layers of the samples at all sliding speeds have only α-Fe phase with a lattice parameter of about 0.287 nm.