The mechanism of nanostructuring the surface of engineering parts during shot blasting

Relevance. The paper considers shot blasting, which is a widely used method for improving the surface properties of parts (such as fatigue strength, hardness, and elongation) due to cold plastic deformation, which results in nanostructuring of the surface of the processed material, accompanied by a reduction in the grain size of its crystal structure. The conditions for the formation of a nanostructured surface layer when processing parts with a shot stream are studied. The aim of the work is to determine the conditions of nanostructuring during shot blasting due to plastic deformation, determined by the impact of the shot, which collides with the treated surface at high speed. Methods. To solve the stated problems, we used the solution of the contact problem of the theory of elasticity on the action of a concentrated force on the elastic half-space, the role of which is played by the workpiece. The conditions of the onset of plastic deformation in the surface layers of the workpiece are determined. Cold plastic deformation provides nanostructuring of the surface layer of the workpiece, increasing strength, fatigue life, atomic diffusion and improving tribotechnical characteristics. Results. Based on the contact problem of the theory of elasticity, the problem of the formation of a nanostructured layer on the surface of the workpiece during shot blasting has been solved. An analytical dependence has been obtained, which allows predicting the transition of the material to a plastic state and nanostructuring the surface of the workpiece during shot blasting.