Estimation of local plastic deformation in a bulk of polycrystalline materials

Abstract

The article deals with the analysis of local plastic deformation after cold forming. The technology of drawing seamless steel tubes was used to obtain cold-formed samples. The tubes were drawn on a Tinius Olsen 300ST tensile tester with a 6 ° and 12 ° die, without and also with a mandrel in the inner diameter. Using stereology and a mathematical model created by the Monte Carlo method, a conversion model of orientation to deformation was created from the data obtained by surface measurements and structure characteristics such as degree of orientation in a given direction, actual (logarithmic) deformation and local stresses were obtained. The experimentally determined values ​​of the actual local plastic deformation were compared with the deformation calculated based on the model simulation in the Deform program. The significance of the differences was assessed by means of a statistical T-test. All differences in the values ​​of the local plastic deformation with respect to the position were evaluated as statistically insignificant, and thus the difference between the experimental calculation and the simulation is random.