23 KB609 KB19 KB200020242012Aytar, Omer BarisCalik, AdnanUcar, Nazimletnik:46številka:6str. 621-625ISSN:1580-2949COBISSID:956330URN:URN:NBN:SI:doc-E0OLQLP8enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijeactivation energyaktivacijska energijaboriranjeboronizinglow-carbon microalloyed steelmaloogljično mikrolegirano jeklomicrohardnessmikrotrdotaTemperature behaviour of the boride layer of a low-carbon microalloyed steel| Temperaturno vedenje boridnega sloja na maloogljičnem mikrolegiranem jeklu|In this work, the boronizing of low-carbon microalloyed steels was carried out in a solid medium using the powder-pack method. After boronizing, a boride layer and the presence of both FeB and Fe2B phases in the boride layer were revealed with classic metallographic techniques and X-ray diffraction (XRD) analysis. The presence and distribution of alloying elements on the boride phases was measured using glow-discharge optical emission spectrometry (GDOES) and the distance between the surface and the substrate was taken as the layer thickness. It was found that higher boronizing temperatures resulted in an increase in the layer thickness, from 7 mum to 105 mum. In addition, microhardness tests of the boronized steel samples showed a significant increase in the surface hardness caused by the increased boronizing temperature. The boride layer had a hardness of over 910 HV0.1 and 1320 HV0.1 for 973 K and 1273 K, respectively, while the substrate's hardness was approximately 145 HV0.1. Kinetic studies showed that the diffusion process is thermally activated, with the mean value of the activation energy being close to 194 kJ/molTo delo obravnava boriranje maloogljičnega mikrolegiranega jekla v trdnem mediju z uporabo metode zasutja v prah. Po boriranju je bila v boridnem sloju odkrita prisotnost FeB in Fe2B s klasično metalografijo in z rentgensko difrakcijsko (XRD) analizo. Po drugi strani pa je bila izmerjena prisotnost in razporeditev legirnih elementov v boridni fazi z obločno razelektritveno optično emisijsko spektrometrijo (GDOES) in razdalja od površine do podlage pomeni debelino plasti. Ugotovljeno je bilo, da višanje temperature boriranja poveča debelino sloja od 7 mim do 105 mim. Dodatno so preizkusi mikrotrdote boriranih vzorcev jekla pokazali občutno povečanje trdote površine boriranih vzorcev s povišanjem temperature boriranja. Boridni sloj je imel trdoto več kot 910 HV0,1 in več kot 1320 HV0,1 pri 973 K oziroma 1273 K, medtem ko je bila trdota podlage okrog 145 HV0,1. Študij kinetike je pokazal, da je difuzijski proces toplotno aktiviran, povprečna vrednost aktivacijske energije pa je bila blizu 194 kJ/molTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije