3199 KB17 KB200020242014Gunes, Ibrahimletnik:48številka:5str. 765-769COBISSID:1097130ISSN:1580-2949URN:URN:NBN:SI:doc-GXPFAWMZenInštitut za kovinske materiale in tehnologijeMateriali in tehnologijeboridingboriranjecold-work tool steelfriction coefficientkoeficient trenjamicrohardnessmikrotrdotaorodno jeklotribological propertiestribološke lastnostiTribological behavior and characterization of borided cold-work tool steel| Tribološko vedenje in karakterizacija boriranega orodnega jekla za delo v hladnem|In the present study, tribological and characterization properties of the borides formed on cold-work tool steel were investigated. Boriding was performed in a solid medium consisting of Ekabor-II powders at 850 °C and 950 °C for 2 h and 6 h. The boride layer was characterized with light microscopy, X-ray diffraction technique and a micro-Vickers hardness tester. An X-ray diffraction analysis of the boride layers on the surface of the steel revealed the existence of FeB, Fe2B, CrB, Cr2B and MoB compounds. Depending on the chemical compositions of the substrates and the boriding time, the boride-layer thickness on the surface of the steel ranged from 13.14 micro m to 120.82 micro m. The hardness of the boride compounds formed on the surface of the steel ranged from 1806 HV0.05 to 2342 HV0.05, whereas the Vickers-hardness value of the untreated steel was 428 HV0.05. The wear tests were carried out in a ball-disc arrangement under a dry friction condition at room temperature with an applied load of 10 N and with a sliding speed of 0.25 m/s at a sliding distance of 1000 m. The wear surfaces of the steel were analyzed using SEM microscopy and X-ray energy-dispersive spectroscopy (EDS). It was observed that the wear rate of the unborided and borided cold-work tool steels ranged from 11.28 mm3/(N m) to 116.54 mm3/(N m)V tej študiji so bile preiskovane tribološke in druge značilne lastnosti boridov, nastalih na orodnem jeklu za delo v hladnem. Boriranje je bilo izvršeno v trdnem mediju, ki ga je sestavljal prah Ekabor-II pri 850 °C in 950 °C v 2 h in 6 h. Boriran sloj je bil preiskan s svetlobno mikroskopijo, rentgensko difrakcijo in izmerjena je bila Vickersova mikrotrdota. Rentgenska difrakcija boriranega sloja na površini jekla je potrdila prisotnost spojin FeB, Fe2B, CrB, Cr2B in MoB. Odvisno od kemijske sestave podlage in časa boriranja je bila debelina boriranega sloja na površini jekla med 13,14 mikro m in 120,82 mikro m. Trdota boridov, nastalih na površini jekla, je bila v razponu od 1806 HV0,05 do 2342 HV0,05, medtem ko je bila Vickersova trdota neobdelanega jekla 428 HV0,05. Preizkusi obrabe so bili izvršeni na napravi krogla-disk pri suhem trenju pri sobni temperaturi z uporabljeno obtežbo 10 N, hitrostjo drsenja 0,25 m/s in pri razdalji drsenja 1000 m. Površina z obrabo je bila analizirana s SEM-mikroskopijo in energijsko disperzijsko spektroskopijo rentgenskih žarkov (EDS). Ugotovljeno je bilo, da je hitrost obrabe neboriranega in boriranega orodnega jekla za delo v hladnem v razponu od 11,28 mm3/(N m) do 116,54 mm3/(N m)TEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaInštitut za kovinske materiale in tehnologije