Influence of the shape of abrasive soil particles on the regularities of destruction of structural steels during wear

Abstract

The article presents the results of studying the patterns of destruction and their influence on the wear resistance of structural steels: steel 45, steel 65G and steel 28MnB5 when moving in soils with different abrasive particle shape factors. The phenomenon of the presence of a critical abrasive particle shape factor (CPSF) was established, up to which the wear resistance of steels decreases. In the supercritical region, wear resistance is stabilized, and the differences between its values of the studied steels are significantly reduced. When forming wear resistance, the role of the particle shape factor is to regulate active deformation and fatigue phenomena by means of the level of external force action on the working surface and is realized through the rheological-fatigue parameter, which is controlled by the cyclic viscosity of steel deformation. In this regard, the choice of structural steel grade for the manufacture of machine parts intended for use in soils with different abrasive particle shape factors must be made based on its ranking by the rheological-fatigue parameter. It is shown that in the strength basis of the steel wear mechanism under sliding friction in soils with different particle shape factors, in addition to the resistance to the propagation of axial and radial fatigue cracks in the destructive deformation layer, an important role is played by the resistance to the initiation and propagation of lateral fatigue cracks at its boundary with the plastic-destructive deformation layer, and the mechanical component of the contact interaction is decisive. It is established that under wear in soils with different particle shape factors, the action of the softening process is more effective than the hardening process. In the supercritical region, the intensity of steel softening is significantly reduced due to the increase in the effectiveness of the hardening action due to the dispersion hardening of steel. However, no qualitative changes in the metal wear process are observed