A gradient strengthening control procedure based on the numerical simulation of the combined local loading of the deformation zone in the form of an algorithm of actions pertinent to the prescription of operational parameters is described. A particular case in the form of the completed nomogram of the treatment parameters prescription for obtaining of strengthening predetermined by the depth and value is presented. Keywords-plastic metal working, combined local loading of the deformation zone, numerical simulation, industrial process control, Odkvist parameter, microhardness, strengthening.P

Numerical mathematical simulation of the strengthening combined local loading of the deformation zone in the process of penetration of indenters of different shapes into the piece body was considered. The simulation results were presented in the form of the pattern corresponding to the Odkvist parameter change depending on the type of the tool and the depth (force) of its penetration into the piece body. Based on the analysis of numerical mathematical simulation data, practical recommendations have been formulated pertinent to the selection of the indenter shape for the processes of gradient strengthening of machine parts in the conditions of combined local loading of the deformation zone. Keywords-numerical mathematical simulation, gradient strengthening of machine parts, combined local loading of the deformation zone, Odkvist parameter, strengthening depth.

A theoretical study of the stress-strain state of helical cylindrical compression springs used in the suspension of vehicles during shot peening is carried out. The stress-strain state of the front suspension spring is studied by mechanical-mathematical methods and methods of the deformation theory of plasticity, in particular, by the method of small elastic-plastic deformations. It is established that shot peening reduces compression of the front suspension springs during pre-stressing by 2.54% due to an increase in the torque in the cross section of the coil by 4.30%. The results of the study can be used in the development of technology for the manufacture and restoration of expensive helical coil springs for the suspension of vehicles, in particular, in determining the required load of contact pre-stressing, taking into account shot peening.

The article discusses some new energy-efficient metal forming processes (PMD) with complex local loading of the deformation zone for the production of machine parts with a given level of properties. The place of such processes in the aggregate of all OMD technologies is shown, and their classification is given. The initial data of numerical mathematical modeling of the specified class of processes for a particular case are given, the features of the stress-strain state of the metal in the deformation zone are revealed. In the study, from a theoretical point of view, one of the important practical aspects of these technologies is considered: the effect of the value of axial compression on the shape and size of the deformation zone arising from the action of local loading of the workpiece.