39 KB1164 KB34 KB200020262008Mandziej, Stan T.Šolar, MojcaVýrostková, A.številka:1letnik:42str. 13-25ISSN:1580-2949COBISSID:686506URN:URN:NBN:SI:doc-K18CPZ5HenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijelezenjemikrostrukturasimulacijezvariAccelerated creep testing of new creep resisting weld metals| Preizkusi pospešenega lezenja zvarov novega jekla, odpornega proti lezenju|New creep-resisting weld metals of P91 grade were manufactured by MMA process producing multi-bead multi-layer test coupons, from which specimens were taken for accelerated creep testing on Gleeble physical simulator. The recently developed accelerated creep testing (ACT) procedure on Gleeble allows transforming in a relatively short time (less than 100 hours) the microstructure of creep-resisting materials near to the thermodynamic equilibrium state, resembling that of multi-years application at creep condition. Such advanced transformation of microstructure in the investigated weld metals after ACT was confirmed with microscopy and microanalytical study. The results also appeared to be in agreement with Thermocalc calculations. Using optimum combination of chemical compositions of the electrodes with welding procedure and post-weld heat-treatment, advantageous mechanical properties were achieved as well as results of ACT indicating potentially long creep life in exploitation conditions. In discussion of the ACT results, comparisons with results of conventional creep testing have been made. The ACT procedure appears to be useful in fast screning of newly developed creep resisting materialsVečvarkovni zvari jekla P91, odporni proti lezenju so bili pripravljeni po MMA-postopku in iz njih so bili izdelani večvarkovni vzorci za preizkuse na simulatorju Gleeble. Pred kratkim razvit preizkus pospešenega lezenja (ACT) nanapravi Gleeble omogoča, da se pretvori v relativno kratkem času (manj od 100 h) mikrostruktura jekla, odpornega proti lezenju, v stanje blizu termodinamičnega ravnotežja, ki je podobno kot po mnogih letih obremenitve z lezenjem. Tako pretvorbo mikrostrukture po ACT smo potrdili z mikroskopsko in mikroanalitsko preiskavo. Zdi se, da so rezultati v skladu z izračuni na podlagi podatkov Thermocalc. Z uporabo optimalne kombinacije kemične sestave lektrod, postopka varjenja in toplotne obdelave po varjenju so bile dosežene dobre mehanske lastnosti in rezultati ACT, ki nakazujejo na potencialno dolgotrajno stabilnost pri obremenitvi z lezenjem. V razpravi primerjamo rezultate ACT z rezultati konvencionalnih preizkusov lezenja. Videti je, da je ACT-postopek koristen za hitro oceno na novo razvitih jekel, ki so odporna proti lezenjuTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije