20.500.12556/DKUM-66572 Fatigue crack initiation from microstructurally small Vickers indentations Nastanak zamorne pukotine iz mikrostrukturno malih vickersovih otisaka The resistivity of coarse grain steel against crack initiation in the presence of micro defects is discussed. Samples of material with martensitic microstructure were prepared by adequate thermal treatment. Microstructurally small Vickers indentations were used as an artificial micro defect. The compressive residual stresses are due to the irreversibility of plastic deformation. The moment of indenting enables to prepare samples with and without effects of residual stresses. The stress level for crack initiation depends on the actual indentation size. The location of initiated cracks is affected by the presence and character of residual stresses. Proučavana je otpornost grubozrnatog dijela zone utjecaja topline na nastanak zamorne pukotine u prisustvu mikro greški. Uzorci materijala s martenzitnom grubozrnatom mikrostrukturom pripremljeni su odgovarajućom toplinskom obradom. Kao umjetne mikro greške upotrijebljene su mikrostrukturno mali Vickers otisci. Tlačna zaostala naprezanja pojave se zbog nepovratnosti plastične deformacije. Moment kad se napravi otisak omogućava pripremu uzoraka s i bez efekata zaostalih naprezanja. Kritičkna razina naprezanja za nastanak pukotine zavisi od stvarne veličine otiska. Na lokaciju nastanka pukotine utječe i prisutnost te vrsta zaostalih naprezanja. welded joints micro defect coarse grain HAZ crack initiation crack growth stress concentration fatigue limit Vickers residual stresses zvarni spoji mikro defekt grobo zrnato TVP nastanek razpoke rast razpoke koncentracija napetosti lomna trdnost Vickers zaostale napetosti true false true Angleški jezik Hrvaški jezik Znanstveno delo 2017-07-03 13:17:50 2017-07-03 13:18:55 2022-08-01 12:55:45 2019-07-11 15:51:54 2007 0 0 str. 237-243 št .4 Letn. 46 2007 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 1334-2576 621.791.051:539.388.1 6892802 11582742 1334-2576 URN:SI:UM:DK:ZYN4AAHT Metalurgija_2007_Vuherer_et_al._Fatigue_crack_initiation_from_microstructurally_small_vickers_indentations.pdf Metalurgija_2007_Vuherer_et_al._Fatigue_crack_initiation_from_microstructurally_small_vickers_indentations.pdf 1 F0CD126F03B71CF7A1AA0327FA43AC59 e7cc62d85403c44672fb46cac85e58743a3e8cb08651f4fa0a515a0c80ab32fd 56955e4a-7c0e-11eb-bb7a-00155d0001ca 20.500.12556/dkum/e4f91264-e789-4fb8-b791-d8accd7c2ec8 https://dk.um.si/Dokument.php?lang=slv&id=113490 http://hrcak.srce.hr/15012 1 https://dk.um.si/Dokument.php?lang=slv&id=113489 Fakulteta za strojništvo 0 0 0