Diffusion kinetics and characterization of borided AISI H10 steel

Abstract

In this study, case properties and diffusion kinetics of the AISI H10 steel borided in Ekabor-II powder were investigated by conducting a series of experiments at temperatures of (1123, 1173 and 1223) K for (2, 4 and 6) h. The boride layer was characterized with light microscopy, X-ray diffraction technique and micro-Vickers hardness tester. The X-ray diffraction analysis of the boride layers on the surfaces of the steels revealed the existence of FeB, Fe 2 B, CrB, Cr 2 B and MoB compounds. Depending on the chemical compositions of the substrates and boriding time, the boride-layer thickness on the surface of the steel ranged from 12.86 μm to 63.72 μm. The hardness of the boride compounds formed on the surfaces of the steels ranged from 1648 HV0.05 to 1964 HV0.05, whereas the Vickers-hardness value of the untreated steel was 306 HV0.05. The activation energy (Q) of the borided steel was 160.594 kJ/mol. The growth kinetics of the boride layer formed on the AISI H10 steel and its thickness were also investigated.