Diffusion kinetics and characterization of borided AISI D6 steel

摘要

In this study, the case properties and diffusion kinetics of AISI D6 steel borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of 1123, 1223 and 1323 K for 2, 4 and 8 h. The boride layer was characterized by optical microscopy, X-ray diffraction technique and microVickers hardness tester. X-ray diffraction analysis of boride layers on the surface of the steels revealed the existence of FeB, Fe2B, CrB and Cr2B compounds. Depending on the chemical composition of substrates and boriding time, the boride layer thickness on the surface of the steel ranged from 13.54 mu m and 164.42 mu m. The hardness of the boride compounds formed on the surface of the steels ranged from 1672 to 2118 HV0.05, whereas Vickers hardness values of the untreated the steels was 584 HV0.05. The activation energies (Q) of the borided steel were 180.359 kJ/mol. The growth kinetics of the boride layers forming on the AISI D6 steel and the thickness of boride layers were also investigated.