20.500.12556/RUL-112618 Izdelava in karakterizacija legirane sive litine s kroglastim grafitom, ki je odporna na toplotno utrujanje Production and characterization of gray cast iron with spherical grafite which is resistant to thermal fatique V magistrskem delu smo se posvetili izdelavi legirane sive litine, ki je odporna na termično utrujanje in je primerna za uporabo tako pri sobni kot pri povišanih temperaturah. Za preiskavo smo uporabili feritno litino, ki jo predpisuje standard ISO EN-GJS 600-10, ki smo ji dodali molibden, da bi primerjali mehanske lastnosti, izvedena pa je bila tudi enostavna termična analiza. V okviru eksperimentalnega dela je bilo izdelanih 7 preizkušancev, ulitih iz iste šarže, na katerih smo izvedli testiranja proti termičnemu utrujanju na fizikalnem simulatorju metalurških stanj Gleeble 1500D. Na simulatorju se je pri temperaturi 600 °C in 200, 500, 1000, 2000 ter 4000 ciklih testiralo 7 vzorcev. Za zagotavljanje gladke površine brez vpliva zareznega učinka med cikličnim obremenjevanjem se je izvedla žična erozija sredinske luknje. Pod emisijskim spektrometrom se je izvedla kemijska analiza vzorcev, izvedel se je natezni preizkus na stroju Instron 5985, pregledana in analizirana je bila mikrostruktura prelomnih površin. S pomočjo svetlobnega in elektronskega mikroskopa smo naredili analizo nastanka in napredovanja razpok, njihovo usmerjenost ter gostoto. S pridobljenimi rezultati smo naredili primerjavo med posameznimi temperaturami in številom ciklov. In the master´s thesis we dealt with production of alloyed grey cast iron, which is resistant to thermal fatique and is suitable for use, both at room and at elevated temperatures. For the investigation we used feritte cast iron which is defined by the ISO EN-GJS-600-10 standard. We added molybdenum in order to compare machanical properties and simple thermal analysis (ATAS) was done. In the experimental work, 7 samples were manufactured from the same batch, on which thermal fatique tests were performed on the Gleeble 1500D physical simulator of metallurgical conditions. On the simulator, samples were tested at 600 °C and 200, 500, 1000, 2000, 4000 cycles. In order to provide smooth surface with no notch effect during cycling testing, the central hole of the specimens was made by electro erosion. Under the emission spectrometer, the chemical analysis of the samples was performed. The tensile test was performed on tensile test machine Inistron 5985 and the microstructure of the fractured surfaces was examined and analyzed. With optical and electron microscopy we analyzed the formation and progression of cracks, their orientation and density. With the final results we made a comparison between the individual temperatures and the number of cycles. siva litina s kroglastim grafitom termično utrujanje razpoke zarezni učinek mikroskopija spheroidal cast iron thermal fatique cracks notch effect microscopy true false false Slovenski jezik Angleški jezik Magistrsko delo/naloga 2019-10-27 07:15:09 2019-10-27 07:15:18 2022-08-24 03:52:02 0000-00-00 00:00:00 2019 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 71371 1847135 4555.pdf 4555.pdf 1 0E628BF76D4B9DFAB187746C8106D040 262970b42d65afa902dc9833a290b4c822fd37d764cdd8f8907877ec6a25c629 ec2ade9a-a1b7-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=124539 Naravoslovnotehniška fakulteta 0 0 0