SUMMARY Friction and wear characteristics of two steels,nominally 0.3%c and 1.3% c-3% Cr,have been investigated using a pin-and -disc wear machine.although only slight differences were exhibited in the wear rate-load curves between the two steels,there was a marked dirrerent in the sliding distance required for the initation of equilibrium mild wear,in which an initial transitory severe wear stage occurs,this initial stage corresponds to a "running-in period TE 99 通用摩擦磨損試驗(yàn)機(jī)