The influence of technological factors on the nature of the distribution of residual stresses on the surface of the workpiece during cutting

Abstract

This article describes the basic information about the residual stresses that occur as a result of mechanical processing. The influence of such technological factors as geometric parameters of the cutting part of the tool, physical and chemical properties and structural and phase state of the workpiece material to be processed, cutting modes (feed, cutting speed, cutting depth) and lubricating and cooling technological means on the nature of the distribution of residual stresses in the surface layer of the workpiece is studied. The literature sources that present experimental studies of the influence of the above factors are analyzed. As a result, it was found that the negative front angle contributes to the appearance of compressive residual stresses on the surface. It was established that an increase in the area of the wear surface leads to a decrease in compressive stresses and the appearance of tension stresses. An increase in the cutting speed leads to a decrease in the amount of tension stresses. However, an increase in the speed when turning steel 45 does not lead to compressive residual stresses, as the heat factor will prevail during processing, and when turning steel 309, a high cutting speed will contribute to the hardening of the surface layer and, as a result, the appearance of residual compressive stresses. Depending on the ductility of the material, an increase in the feed can lead to both compressive residual stresses and tension stresses. This is due to the fact that when using other materials, heating can lead to quenching or tempering of the surface layer and, accordingly, to other results that will depend on the phase structural transformations occurring in the material. However, the effect of cutting coolant is ambiguous and will depend on how much heat is released in the cutting area. Thus, knowing the operating conditions of the product, it is possible to adjust the nature of the distribution of residual stresses on the surface by changing certain technological factors.