Estimation of Local Plastic Deformation in a Bulk of Polycrystalline Materials

Abstract

The article deals with the local plastic deformation analysis after cold forming. The technology of drawing seamless steel tubes was used to obtain cold-formed samples. The tubes were manufactured by a Tinius Olsen 300ST tensile tester with a 6 ° and 12 ° die drawn without and with an inner mandrel. Based on orientation size recalculated by stereology and applying Monte Carlo method a mathematical conversion model was developed. Implemented model together with surface measurements and structure characteristics were used to get the orientation to the size of the deformation. Thus, the actual (logarithmic) deformations and local stresses were determined. Comparison of experimentally measured values of the actual local plastic deformation with the deformation calculated found on the model simulation in the Deform program defined the significance of the differences 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 therefore the difference between the experimental calculation and the simulation is random.