In the present work an acoustic emission (AE) technique is used to detec: the initiation and propagation of short cracks in compressive cyclic loading. A mild steel surface was subjected to cyclic compressive stress of 100 cycles s’ by an electromagnetic exciter system. The compressive load applied was in the range of 2.5 to 25 N in each cycle. The stressing was done with an En31 steel ball in the presence of turbine oil. Acoustic emission was deteced by placing an AE sensor 1.5 cm away from the point of contact of ball and plate. The surface damage was observed to be negligible until IO4 cycles. Microcrack nucleation and/or growth were inferred until 0.6 x IO5 cycles. Thereafter the acoustic
emiss,ion activity decreased, suggesting possible arrest mechanisms were operating. The emission activity again became very significant beyond 6.0 x IO5 cycles, which may be due to possiole subsurface crack growth. This information is related to previous one-pass sliding experiments.