Investigation of diffusion kinetics of plasma paste borided AISI 8620 steel using a mixture of B2O3 paste and B4C/SiC
Özet
In the present study, AISI 8620 steel was plasma paste borided by using
various B2O3 paste mixture. The plasma paste boriding process was carried out in a
dc plasma system at temperatures of 973, 1023 and 1073 K for 2, 5 and 7 h in a gas
mixture of 70% H2 -30% Ar under a constant pressure of 10 mbar. The properties
of the boride layer were evaluated by optical microscopy, X-ray diffraction, Vickers
micro-hardness tester and the growth kinetics of the boride layers. X-ray diffraction
analysis of boride layers on the surface of the steel revealed FeB and Fe2B phases.
Depending on temperature and layer thickness, the activation energies of boron in
steel were found to be 124.7 kJ/mol for 100% B2O3.
