Friction and wear of spheroidal graphite cast iron under severe sliding conditions

摘要

The dry friction and wear characteristics of spheroidal graphite cast iron under the severe conditions of high sliding speed and high contact pressure were experimentally investigated by using the pin-on-disk type test rig. The variations of the friction force, the wear amount and the temperature rise with sliding distance were experimentally measured and the relations among them were clarified. The friction and wear characteristics of spheroidal graphite cast iron pin are strongly influenced with the friction-induced temperature rise. Its wear rate changes in three steps as the increment of sliding distance because of the changes of its hardness by temperature rise (the first wear region, the second wear region and the third wear region). The wear rate of cast iron pin depends on the sliding speed and the contact pressure, and its empirical formula in each region was derived. Meanwhile, the coefficient of friction is large at the start of sliding and rapidly decreases with the increment of sliding distance in the first and the second wear regions. Finally, it converges to some constant value in the third wear region. The coefficient of friction depends on the sliding speed and decreases with its increment, but it is almost independent of contact pressure. Some empirical formulae were derived.