Yazar "Bayca, S. U." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    The Effect of Solid Boriding Time on the Structure, Hardness and Corrosion Properties of AISI 5140 Steel
    (MAIK NAUKA/INTERPERIODICA/SPRINGER, 2020) Bayca, S. U.; Bican, O.; Yamanel, B.; Hekimoglu, A. P.; Calis, M.
    In this study, AISI 5140 steel samples were borided in an electrical furnace at a temperature of 950 degrees C for 4, 6 and 8 h. Structural examinations, hardness measurement and corrosion tests were performed to determine the effect of the boriding time on the microstructure, hardness and corrosion resistance of the steel surface. It was observed that 4 h of boriding treatment resulted in the forming of Fe2B layer on the surface of the AISI 5140 steel. However, when the boriding time exceeded 4 h, FeB phase formed on the surface layer of the steel in addition to the Fe2B phase. It was also observed that both the thickness and hardness of the boride layer increased with the increasing boriding time. The hardness values of the borided sample surface were approximately seven times greater than unborided AISI 5140 steel. The samples subjected to boriding for 4 h showed higher corrosion resistance than the unboriding steel samples. But boriding time of more than 4 h caused a decrease in the corrosion resistance of the AISI 5140 steel.
  • Küçük Resim
    Öğe
    Investigation of Leaching Kinetics of Ulexite Waste in Oxalic Acid Solutions
    (Croatian Soc Chemical Engineering Technology, 2014) Bayca, S. U.; Kocan, F.; Abali, Y.
    The dissolution of ulexite waste in oxalic acid solutions was studied in a batch reactor after characterization of the waste by X-ray diffiaction (XRD) analysis and X-ray fluorescence (XRF) analysis. The dissolution parameters in this study were acid concentration, stirring rate, and reaction temperature. The experimental data were examined using homogeneous and heterogeneous kinetic models, and the dissolution kinetics of the waste was determined to be a first-order reaction control model. The activation energy of ulexite waste in oxalic acid solution was also calculated. It was observed that the dissolution rate increased with increasing reaction temperature, stirring rate and acid concentration. The kinetic model of the dissolution process was determined to be a first-order reaction control model. The activation energy was found to be 41.09 kJ mol(-1).