Browsing by Author "H. Djebaili"

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    Characterization of precipitates in a 7.9Cr–1.65Mo–1.25Si–1.2V steel during tempering
    (2009-03-11) H. Djebaili
    In this paper, the precipitates formed during the tempering after quenching from temperature 1150 °C for 7.90Cr–1.65Mo–1.25Si–1.2V steels are investigated using an analytical transmission electron microscope (A-TEM).The study of this tempering is carried out in isothermal and anisothermal conditions, by comparing the results given by dilatometry and hot hardness. Tempering is performed in the range of 300–700 °C. Coarse primary carbides retained after heat treatment are V-rich MC and Cr–Mo-rich M7C3 types. In turn, it gives a significant influence on the precipitation of fine secondary carbides, that is, secondary hardening during tempering. The major secondary carbides are Cr–Mo–V-rich M′C (and/or) Cr–Mo-rich M2C type. The peak hardness is observed in the tempering range of 450–500 °C. In the end, we observe between 600 and 700 °C, that this impoverished changes the phase. At these high temperatures of tempering, we observe that there is a carbide formation of the types M6C developing at the expense of the fine M7C3 carbides previously formed
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    Effect of MoZrN Coating on a Steel XC100
    (JOURNAL OF NANO- AND ELECTRONIC PHYSICS, 2016-04-12) A. Abboudi; B. Meddour; B. Chermime; H. Djebaili; M. Brioua
    The zirconium nitride ZrN coatings are deposited on substrates of XC100 steel using physical vapour deposition (PVD) technique. Coatings based on nitrides of transition metals (Nb, Zr, Ti, V, ) developed by PVD are known to increase the life of cutting tools, and so they naturally have seen a rapid industrial growth. It is possible to produce ZrN-coatings with variations of nitrogen partial pressure, the residual stresses, the thickness of the thin film, and the friction coefficient depending on the nitrogen content. Usage of nitrogen is a good way to enhance wear resistance and effectiveness in tribological applications.