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Processes of cold plastic forming are characterized by unity of positive and negative influence of outer friction forces ; on some contact surfaces of material and tool the friction should be intensified, and in other zones the friction forces must be reduced by lubrication as much as possible. By proper selection of influential process parameters it is possible to obtain work piece of satisfactory quality with minimal energy consumption. In this paper, a detailed analysis of influence of specified parameters on total ironing force and friction force on punch will be shown on adequate model of sheet-metal test-piece sliding between pairs with skewed contact surfaces. The obtained results indicate the complex effects of selected analyzed parameters of ironing process on ironing force.

The automatization of open-die forging technology is essential for cheaper production and better quality products. The current models for the prediction of spreading are too general and, consequently, not sufficiently accurate, which was confirmed by using Hot Forging Simulator software (HFS). The metods applied for the model development that include more influential parameters, are the following: the registration of parameters and measurements of workpiece spreading during the laboratory physical simulations; industrial measurements; the analysis of local material flow with the FE method; the treatment of measurement results and analysis with neuronal networks. Two models for the prediction of free spreading were proposed: prediction in the form of a function and prediction by applying neuronal networks. The accuracy of the predictions with both new models is much better than that with the current model. Avtomatizacija tehnologije toplega prostega kovanja je bistvenega pomena za izboljšanje gospodarnosti proizvodnje in kvalitete izdelkov, kovanih na hidravlični stiskalnici. Dosedanji modeli napovedovanja prostega širjenja so za ta namen presplošni in premalo natančni, kar je bilo potrjeno tudi z njihovo uporabo v programu za simulacijo toplega prostega kovanja HFS (Hot Forging Simulator). Pri razvoju novega modela, ki upošteva večje število vplivnih parametrov, so bili uporabljeni naslednji postopki: spremljanje parametrov in merjenje širjenja vzorcev med fizikalnim simuliranjem v laboratoriju; meritve parametrov kovanja v industriji; analiza lokalnega toka materiala z metodo končnih elementov in obdelava rezultatov meritev in analiz z nevronskimi mrežami. Za napovedovanje prostega širjenja sta bila uporabljena dva načina: funkcijski zapis in napovedovanje z uporabo nevronskih mrež. Natančnost napovedovanja z obema modeloma je veliko večja kot pri sedaj uporabljenem modelu.