20.500.12556/RUL-173529 Napovedovanje razvoja mikrostrukture med vročim valjanjem titana diplomsko delo Predicting microstructure evolution during hot rolling of titanium diploma work Cilj diplomskega dela je bil napovedovanje razvoja mikrostrukture komercialno čiste titanove zlitine z oznako Grade 2 med vročim valjanjem. V ta namen so bila orodja, ki vključujejo simulacije utrjevanja, dinamične poprave in rekristalizacije ter so bila razvita za jekla, ustrezno modificirana in prilagojena za titan. Na osnovi mikrostrukture analiz industrijsko valjanega materiala ter na osnovi dostopne znanstvene literature so bili določeni materialni parametri, tako da je bila razlika med industrijskimi in simuliranimi mikrostrukturami minimalna. S temi parametri je bila izvedena serija simulacij, kjer smo študirali vpliv različnih tehnoloških parametrov, kot so hitrost valjanja, temperatura ter različni časi med posameznimi deformacijami, na razvoj mikrostrukture oziroma na končne velikosti kristalnih zrn. Prav tako je bila izvedena parametrična analiza na podlagi študij občutljivosti različnih materialnih parametrov na kinetiko procesov v materialu. Simulacije so pokazale, da se za izbrani nabor parametrov velikost zrn povečuje z večanjem hitrosti valjanja, kar smo pripisali povečanemu razpoložljivemu času, ki je na razpolago za normalno rast zrn. Po drugi strani pa se je velikost zrn z nižanjem temperature valjanja manjšala, kar je pričakovan rezultat. Rezultati simulacij so pokazali, da spreminjanje časov med posameznimi deformacijami v časovnih intervalih, ki jih dopušča valjarna v podjetju SIJ Metal Ravne, nima bistvenega vpliva na končno mikrostrukturo. Simulacije kažejo na dobro napovedno moč modificiranega modela ter občutljivost na spreminjanje procesnih ter materialnih parametrov, zato bi bilo lahko z nadaljnjim razvojem in prilagoditvami odlično orodje in pripomoček tehnologom pri načrtovanju tehnologij vročega valjanja tudi za druge kakovosti. The aim of the diploma work was to predict the evolution of the microstructure of a commercially pure titanium alloy Grade 2 during hot rolling. For this purpose, tools that were originally developed for steels and include simulations of strain hardening, dynamic recovery and recrystallisation were modified accordingly and adapted for titanium. Based on microstructural analyses of industrially rolled material and available scientific literature, the material parameters were determined in such a way that the difference between the industrial and simulated microstructures was minimal. With these parameters, a series of simulations were carried out to study the influence of various technological parameters, such as rolling speed, temperature and different times between individual deformations, on the evolution of the microstructure, i.e. on the final grain size. In addition, a parametric analysis was carried out to study the sensitivity of various material parameters on the kinetics of the processes taking place in the material. The simulations showed that the grain size increases with increasing rolling speed for the selected parameters, which was attributed to the longer time available for normal grain growth. On the other hand, the grain size decreased with decreasing rolling temperature, which is an expected result. The simulation results also showed that changing the times between each deformation within the time intervals allowed by the rolling mill at SIJ Metal Ravne has no significant effect on the final microstructure. The simulations show the good predictive capability of the modified model as well as its sensitivity to variations in process and material parameters. Therefore, with further development and adjustments, it could become an excellent tool and aid for technologists when planning hot rolling technologies for other grades as well. titan Grade 2 valjanje modeliranje rekristalizacija velikost zrn titanium Grade 2 rolling modeling recrystallizacion grain size true false false B. Prapertnik Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-09-18 09:00:37 2025-09-18 09:00:45 2025-11-14 11:52:00 0000-00-00 00:00:00 2025 0 Ljubljana 0 Ljubljana XII, 45 f. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 669 108527 257239299 26736.pdf 26736.pdf 1 DE671C614A1242DF81A7DE4222044278 c2281f458f5c4f1e1f86cf6b9e8ad05e1dfb293100d8b75f4cf855e1d396b2b6 060462cd-945d-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=218047 Naravoslovnotehniška fakulteta 0 0 0