Product durability management using surface engineering technologies

Abstract

The problem of managing the durability of products due to the creation of regions in materials with a given temporal and spatial non-locality is considered. A mathematical model of softening of materials under the action of external loads is proposed, allowing to take into account the special role in the formation of damaged places of exit of grain boundaries and their triple junctions on the outer surfaces of parts, as well as their interaction with stress concentrators formed after mechanical processing.
 The developed model representations are used to ensure the operational uniformity of structural elements with concentrators under stress by methods of surface engineering, in particular, when determining the role of changes in the quantitative parameters of the microstructure on the wear resistance of the surface layers of rolling stock parts of railway transport containing stressed concentrators. The optimal depth of the plasma hardening of the subsurface layers of the rims of wheel pairs of locomotives has been established, depending on the size, placement and geometric characteristics of the tension concentrators. It is shown that taking into account the dynamics of structural changes during the degradation of materials in the conditions of operation according to the proposed model ratios allows to achieve the specified life cycle of parts at minimal costs.
 Increasing the durability of products is achieved by optimizing technological modes of surface engineering, which ensure the formation of structures with a smaller gradient of properties.