Effect of microstructure on the erosion of steel by solid particles

The effect of microstructure on the erosion of AISI-SAE 1078 and 10105 steels by 240 grit A1₂O₃ particles was investigated at particle velocities V of 40–100 m s^?1 and angles of impingement a of 10°–90° relative to the target surface. The microstructures investigated included spheroidite, pearlite, martensite and tempered martensite.Spheroidite and pearlite microstructures eroded by the ductile mode at all velocities, exhibiting a maximum erosion rate at an impingement angle of 40°. The effect of the angle of impingement on the erosion rate of martensite and tempered martensite varied with particle velocity, the erosion mode tending towards a brittle mode with increasing velocity. At all angles of impingement the erosion rate tended to increase with the volume fraction of Fe₃C. Examination of the eroded surfaces by scanning electron microscopy showed the occurrence of localized plastic flow of appreciable magnitude. No subsurface cracking or void formation was evident. The erosion rate E_r could be considered to vary with particle velocity according to the power law E_r = kVⁿ where n has a value of about 2 independent of the microstructure and the angle of impact.