Design of mechanical properties of structural materials for power plant equipment

Abstract

External impulse action on structural materials allows changing their mechanical properties. Such changes occur primarily in the surface layer of the material. One of the simplest methods of such an effect is to apply electrical impulses to metallic materials. Many different hypotheses have been proposed to explain the processes involved. In this paper, experimental data are presented that show that such hypotheses do not satisfactorily explain the observed phenomena. The results obtained show that the description of processes in the surface layer of a metal under the influence of an electric pulse should take into account the observed phenomena. This is the influence of the polarity of the applied electrical signal, the wave characteristics of the generated damped oscillatory processes, the synchronization of such processes with the moments of the beginning of the leading and trailing edges of the applied electrical pulse, the linear nature of the dependence of the amplitude of the vibration response on the amplitude of the applied pulse. The indicated features are manifested both in the region of elastic and plastic deformations of the metal. Such phenomena are observed for samples in the presence of additional static loading, and without it. The need for an adequate understanding of the processes occurring in this case is necessary for the effective application of methods related to the effect of electric pulses on metals. Such solutions are widely used to control the properties of materials in the processing of metals using cutting, drawing, when performing electric-pulse welding and the creation of non-destructive testing at the stages of production, operation and repair of various industrial equipment.