Optimisation of multi step hot bulk forging

Diplomska naloga izhaja iz izdelka, narejenega za potrebe udeležbe na mednarodnem tekmovanju International Students Olympiad in Hot Bulk Forging technologies of 2018, na katerem je bilo treba izdelati geometrijo vroče kovanega izdelka, ki bi čim boljše izpolnjeval zahtevane parametre. Glavni tehnološki proces je kovanje v utopih. Vrednotenje je potekalo v programskem okolju QForm 3D, ki obsega dvodimenzionalne simulacije kovanja z uporabo končnih elementov. Na podlagi rezultatov, ki so bili pridobljeni v času tekmovanja, se je nato izvedla še optimizacija izdelka, s ciljem čim višje porabe materiala ter zadovoljive življenjske dobe orodja. Končen rezultat je bila ustrezna geometrija orodja z dovoljšno življenjsko dobo ob 68,5% izkoristku materiala. Ta rezultat je bil pridobljen ob smiselni spremembi geometrije, ki ni sledila smernicam standardov DIN 7523 ter EN DIN 10243. Pomembno je vplivala pravilna izbira maziva, uporaba ponovnega gretja med postopki kovanja, ter uporaba sestavljenega orodja, ki je pripomoglo k prednapetju samega orodja. Zelo pomembna pa je bila tudi zasnova nakrčevanja, ki je odločilno prispevala k izboljšanju življenjske dobe orodja.This Bachelor\u27s thesis picks up from the report, which was used for participating in the International Students Olympiad in Hot Bulk Forging technologies of 2018. The main objective of the competition was to create a suitable geometry for a hot forged closed-die part, which would fulfil the required criteria as well as possible. The evaluation of the forging procedure was done with the help of QForm a finite element simulation environment. Based on the results of the simulations, which were obtained during the Olympiad, the optimisation procedure took place after the competition, in order to improve on the metal utilisation factor and tool life expectancy. The end result achieved a suitable tool geometry with a sufficient tool life expectancy along with a 68,5% metal utilisation factor. The results were achieved without following the guidelines from the DIN 7523 and EN DIN 10243 standards for hot steel forging, but were changed accordingly. This resulted in a higher metal utilisation factor. Along with a high metal utilisation factor the high tool life expectancy was achieved with a combination of factors, such as reheating of the parts between the various stages of forging, the use of assembled tools. The suitable design of the upsetting stage also contributed to a high tool life