| الوصف: |
V zaključnem delu »Lasersko pretaljevanje površin ogljikovih jekel C15 in C45« je predstavljena metodologija eksperimenta in ovrednotenje dobljenih rezultatov mikrostruktur in mikrotrdote kot posledica laserskega pretaljevanja Nd:YAG laserja dveh ogljikovih jekel z oz. brez zaščitnega plina Ar. S pomočjo meritev globin in širin pretaljenega in toplotno vplivanega območja ter meritev mikrotrdot v pretaljenem, toplotno vplivanem območju in osnovnem materialu smo določili optimalne procesne parametre, katerih cilje je bil, da s procesom laserskega pretaljevanja čim bolj utrdimo material, hkrati pa imamo čim večjo učinkovitost. Na podlagi analize rezultatov mikrostruktur in mikrotrdot se je izkazalo, da smo pri danih konstantnih in spreminjajočih veličinah optimalen parameter obdelave pri C15 dobili pri uporabi energije žarka E = 13,7 J, pri C45 pa pri E = 11,9 J. Poleg omenjenih energij žarka smo imeli še konstantni parametre t = 8ms, f = 4 Hz, v = 1.5 mm/s in ?v_Ar = 2 l/min. Po ovrednotenju meritev smo lahko opazili, da je C45 veliko bolj primeren material za lasersko utrjevanje površin, saj se v primerjavi z C15 začne pretaljevati že pri manjših močeh, prav tako je to pretaljevanje in vnos toplote v material skozi celoten potek bilo intenzivnejše v globino materiala. In final thesis »Laser surface remelting of carbon steel C15 and C45« are presented methodology of an experiment and evaluation of the obtained results of microstructures and microhardness as result of laser surface remelting with Nd:YAG laser of two carbon steels with or without Ar gas protection. With help of measuring depths,widths and microhardness of remelted and heat-affected area and base material, we determined the optimal process parameters, whose goals were to harden material as much as possible and while doing that, we also wanted the biggest efficiency Based on the analysis of the results of microstructures and microhardnesses, it turned out that for given constant and changing values, the optimal processing parameter for C15 was obtained when using the beam energy E = 13.7 J and for C45 at E = 11.9 J. Beside mentioned beam energies, we also had constant parameters like t = 8ms, f = 4 Hz, v = 1.5 mm/s and Φv_Ar = 2 l/min. After evaluating the measurements, we could see that C45 is a much more suitable material for laser hardening of surfaces as C15, since it begins to remelt at lower powers and in addition, also remelting and heat input into material throught the whole process is more intense to the depth of material. |
