19 KB727 KB13 KB199219991999Medved, JožeMrvar, PrimožTrbižan, Milanštevilka:1/2letnik:33str. 45-49ISSN:1318-0010COBISSID:137642URN:URN:NBN:SI:doc-SXSTG6O1slInštitut za kovinske materiale in tehnologijeŽelezarna JeseniceŽelezarna RavneŽelezarna ŠtoreKovine zlitine tehnologijedilatometrijalito železomikrostrukturastrjevanjeSpremljanje strjevanja železovih litin z dilatometrijo| Investigation of cast iron solidification with dilatation analysis|The cast iron solidification and the dilatation analysis have been investigated. Computer-added dilatometer has been designed and verified into the practice. The results of measurements the dilatations in dependence of temperature and time are shown in dilataometric curves. The investigations have been taking place on the lamellate graphite and spheroidal graphite cast irons. The results have been verified by the thermal analysis and metallographic examinations. It is possible to detect exactly the precipitation of graphite as independent phase by eutectic solidification and eutectoid transformation. Therefore the information about the graphite growth in the eutectoid transformation has been enabled in order to find out the proportion between the perlite and ferrite phase in the matrix of the SG cast iron. Such investigation of melts would made possible the correction of the composition cast melt before the castingRaziskava obravnava dilaatometrijsko analizo strjevanja železovih litin. Izdelali smo in preverili računalniško podprt dilatometer. Rezultate meritev dilatacij in tempeatur v odvisnosti od časa, kot tudi dilatacije v odvisnosti od temperature, smo prikazali na dilatogramih. Preiskovali smo sivo litino z lamelnim in s kroglastim grafitom. Preverjanje je potekalo s primerjavo dilatogramov v povezavi s termično in metalograsko analizo. Z dilatogrami in diferenciranimi dilatometrijskimi krivuljami stabilno strjenih litin je bilo mogoče natančno spremljati izločanje grafita kot samostojne faze, tako pri evtektski kot pri evtektoidni premeni. Uporabno vrednost daje metodi predvsem podatek o razavoju grafita pri evtektoidni premeni, iz katerega lahko ugotavljamo razmerje med perlitom in feritom v mikrostrukturi nodularne litine. Taka preiskava staljene litine bi v praksi omogočila sestave taline še pred ulivanjemNadaljuje se kot: Materiali in tehnologijeTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije