Estimation of Local Plastic Deformation in a Bulk of Polycrystalline Materials
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.