Reasons and kinds of marriage depending on the formation of the stress-deformed condition and evaluating the probability of destruction of the cross-border on the criteria of Cockroft-Letem in the process of cold volume stamping combined by the method of pressing-expansion

In this paper, the data on the stress-strain state of the billet during the combined “crimping-distribution” process. The probability of destruction of a billet during the course of operations at its dangerous stages is considered. The main types of marriage are identified, such as the formation of cracks, crushing, under-shaping. The recommendations and reasons for its occurrence are given. For the prevention of cracks, it is proposed to conduct annealing to relieve internal stresses. Do not crush the workpiece. We bring to your attention several options for use: As a rule, except when they can not be processed. Also, during model simulation, the model did not match the actual data. The received discrepancy consists in occurrence of probability of destruction of a stamped blank in a crimped part that contradicts the experimental data. Within the framework of this, for a better and more reliable analysis of fracture, a correction criterion was introduced that takes into account the value of the average stresses over the height of the billet. The introduction of a new criterion in a more complex and reliable form, the destruction of the preparation in the process of deformation in the program complex. It is carried out by comparison of the level of the experimental data and the results of the simulation. On the basis of the obtained data, the applicability of the correction criterion in practice and the possibility of its application in the compilation of technological regimes in research and industrial exhibitions are confirmed. In the future, it is planned to compile a mathematical model for the purpose of determining kinematic and energy-force parameters.