Investigation of diffusion kinetics of borided AISI P20 steel in micro-wave furnace

Abstract

In present study, kinetics of borides formed on AISI P20 steel has been investigated by boronizing treatment which was carried out in Ekabor-II powders at the process temperatures of 1123, 1173 and 1223 K for 2, 4 and 6 h in both micro-wave (M.F) and conventional atmospheric furnace (C.F). The properties of boride layer were evaluated by optical microscopy, X-ray diffraction and micro-Vickers hardness tester. The growth kinetics of the boride layers forming on the AISI P20 steel and thickness of boride layer were computed. The present phases in boride layers of borided AISI P20 steel were FeB, Fe2B, CrB and MnB respectively.

The thickness of Boride layer formed on the surface of AISI P20 steel ranged from 26 to 143 μm in conventional furnace and ranged from 33 to 158 μm in microwave furnace with varying boriding temperature and time. Depending on temperature and layer thickness, the activation energies of boron for AISI P20 were determined to be 256.485 kJ/mol in conventional furnace and 213.935 kJ/mol at microwave furnace.