Erosive wear by silica sand on AISI H13 and 4140 steels

The erosive wear behaviour of AISI H13 tool steel and AISI 4140 steel has been investigated in this work using a sand blast-type rig. Samples of six different hardness levels (from annealed to 595 HV) were produced and subsequently tested using silica sand as the erodent material at impact angles ranging from 10° to 90°, air drag pressures of 0.689 and 1.38 bar (10 and 20 psi respectively), impact speeds ranging from 70 to 107 m s⁻¹ and various particle sizes. Results of erosion versus impact angle at different hardness levels showed three distinctive wear regions: (i) for impact angles of 10° and 20°, the amount of wear was higher at lower hardness values; (ii) for impact angles of 30° and 40° no significant changes were found in the amount of wear despite the increase in hardness; (iii) for impact angles of 60°, 75° and 90° the amount of wear was higher for higher hardness levels in the eroded material. Single curves showed typical ductile behaviour of these alloys, a transition towards brittle behaviour for the hardest specimens was also observed due to the formation of adiabatic shear bands. SEM analysis was conducted to identify the erosion mechanisms for each type of behaviour.