Effect of Low-temperature on the Tribological Properties of the Different Material of Marine Hydraulic Vane Motor

Conventional marine hydraulic motors may not be suitable due to the effects of polar temperature environments. In this paper, for the same type of marine hydraulic vane motor, the friction and wear tests were carried out on the vanes of different materials to analyze the influence of low temperature environment on the friction and wear properties of different materials. The material of conventional marine hydraulic motors vanes was spring steel and the material of polar marine hydraulic motors vanes was martensitic stainless steel. The sliding wear tests of the two materials were performed against ductile iron discs by using wear tester under different temperature conditions respectively. In order to analyze the wear mechanism of the friction test specimen under different conditions, the surface morphology of the friction test was carried out by Scanning electron microscope (SEM). The results showed that the coefficient of friction between the pin samples of the two materials and the disk samples of ductile iron didn't change linearly as the temperature decreases. The factors were that the mechanical properties of the material and the rheological properties of the lubricating medium changed strongly and nonlinearly at low ambient temperatures. In general, between 25°C and -10°C, the friction pairs of the two materials and ductile iron were comparable. The disc samples of spring steel and ductile iron wear more serious when the temperature dropped down -10°C. Its ploughing was deeper and cracks appeared. According to the experimental results, the wear mechanism of the friction pair composed of two materials were summarized, which not only optimized the design of the hydraulic motor, but also provides reference data for establishing the online intelligent fault diagnosis system for marine hydraulic system.