Study on the wear properties of impregnated graphite materials of the circumferential seal with the same PV value but different speed or load

This study investigates the effects of different speeds and loads with the same PV value on the wear properties and mechanisms of impregnated graphite materials. A self-developed high-temperature, high-speed friction and wear tester was used to conduct wear tests on the pair of graphite and GH4169 material under three different operation circumstances for 3 h. A machine vision-based method was used to measure wear volume. Results show that under the high-load, low-speed combination, graphite wear is significantly higher than under the low- load, high-speed combination. At a PV value of 7.5 MPa & sdot;m/s, when the load is increased by a factor of about one and the speed is decreased by a factor of approximately one, the 3-h average wear rate increases by a factor of 4.1. Examination of the friction surface morphology and elemental composition of the graphite and ring track after the test revealed that abrasive and adhesive wear are the primary wear types. Subsequently, a quantitative analysis of the ratio between abrasive and adhesive wear was performed using simulation methods. The results show that as speed increases and load decreases, the proportion of adhesive wear on the graphite increases. The work in this paper is valuable for studying graphite seal material selection and lifespan projecting.