Simulation model of contact interaction during surface strengthening of steel parts

Abstract

In the processes of surface strengthening of steel parts, the stress-strain state is decisive for explaining the physical processes of strengthening, forming the dimensions of the contact area. Analytical dependences of contact parameters are quite approximate. In this work, based on the Ansys software complex, a simulated model of the contact of a truncated torus with a cylinder is proposed, which demonstrates the kinetics of the process of pressing a hard alloy tool into a steel workpiece - a cylinder. The experiment was conducted for 4 seconds in order to determine the maximum level of stresses, the distribution of stresses and the amount of residual stresses after removing the load. The clamping force was applied mainly in the zone of elastic deformations. The results showed an uneven stress distribution with a maximum in the center of the contact spot of 1082 MPa. After changing the load direction, small residual deformations at the level of 0.00311 μm were observed in the center of the contact patch. This indicates a violation of the elastic region on a small contact area, which does not affect the general nature of the stress distribution and can be removed during the finishing process. The results of simulation of the stressed state are used for the correlation with the observed structural changes of the material during the action of thermal and power stresses. The stress peak was formed at a distance of 200 μm, which contributes to the formation of maximum values of microhardness at this depth.

Keywords

• stress-strain state, surface, strengthening, contact processing, tool, truncated torus, cylinder, elastic deformations