207 KB24 KB200020242014Abdellah, Zahra NaitKeddam, Mouradštevilka:2letnik:48str. 237-242COBISSID:1047722ISSN:1580-2949URN:URN:NBN:SI:doc-1JFBNI12enInštitut za kovinske materiale in tehnologijeMateriali in tehnologijeannealingboridingboriranjeFickovi zakoniFick's lawsgrowth kineticsincubation timesinkubacijski časkinetika rastisimulacijasimulationžarjenjeEstimation of the boron diffusion coefficients in FeB and Fe2B layers during the pack-boriding of a high-alloy steel| Določanje koeficienta difuzije bora v plasteh FeB in Fe2B med boriranjem visoko legiranega jekla v skrinji|In this work we propose a diffusion model to estimate the boron diffusion coefficients in FeB and Fe2B layers during the pack-boriding of AISI M2 steel in the temperature range 1173-1323 K for a treatment time of 4-8 h. The proposed model is based on the mass-balance equations at the two growth fronts- FeB/Fe2B and Fe2B/substrate - under certain assumptions. The estimatedvalues of the boron activation energies in the FeB and Fe2B layers were compared with the literature data. The present model was extended to predict the thickness of each boride layer for the borided samples at different temperatures for 10 h. Iso-thickness diagrams were established to beused as a tool for predicting the thickness of each boride layer as a function of the two parameters: temperature and time. Finally, a simple equation was proposed to estimate the required time to obtain a single Fe2B layer by diffusion annealingPredstavljeno delo predlaga model difuzije za določanje koeficienta difuzije bora v plasteh FeB in Fe2B med boriranjem v skrinji jekla AISI M2 v temperaturnem območju 1173-1323 K pri spreminjanju trajanja postopka od 4 h do 8 h. Predlagani model temelji na enačbi masne balance na dveh rastočih mejnih ploskvah (FeB/Fe2B) in (Fe2B/osnova) pri določenih predpostavkah. Določena vrednost aktivacijske energije bora v FeB- in Fe2B-plasti je bila primerjana s podatki iz literature. Predstavljeni model je bil razširjen, da bi lahko napovedal debelino vsake od obeh boridnih plasti za borirane vzorce pri različnih temperaturah in trajanju do 10 h. Postavljeni so bili diagrami enake debeline, ki so uporabni kot orodje za napovedovanje debeline vsakega od boriranih slojev v odvisnosti od dveh parametrov (temperature in časa). Predlagana je preprosta enačba za določanje potrebnega časa za nastanek plastiFe2B z difuzijskim žarjenjemTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije