Simulation of Microcontact Interactions during Gas-Abrasive Wearing of Steels with Allowance for Strain Hardening

In this paper, we present a model of the effect of the contact interaction velocity and the mechanical properties of contacting materials on contact stresses and deformations in carbon structural steels caused by a solid particle flow. The existence of three critical states of the material exposed to impact deformation is considered. The first state is characterized by the formation of a plastic flow zone in the surface layer (transition from perfectly elastic to constrained elastic–plastic deformation). The second state is characterized by the exit of this zone to the part surface (transition from constrained elastic–plastic deformation to a free plastic flow, i.e., dynamic indentation). The third state is characterized by the destruction of surface layers due to tensile stresses on the contour of the contact spot values equal to the true tensile strength of the deformable material under tension with allowance for strain hardening. The characteristic values of the dynamic microcontact interaction velocities that correspond to the ranges of the existence of each of the critical state forms were determined. The dominant mechanisms of erosive wear of parts for each of the states (multi-cycle fatigue wear for the first state, low-cycle fatigue wear with an incubation period for the second state, and intensive formation of erosion damage with a minimal incubation period for the third state) were indicated.