Keddam, M., Ortiz-Domínguez, M., Gómez-Vargas, O. A., Arenas-Flores, A., Flores-Rentería, M. A., Elias-Espinosa, M., García-Barrientos, A. (2015), Kinetic study and characterization of borided AISI 4140 steel. Materiali in tehnologije/Materials and technology, 49 (5), 665?672
In the present study, an alternative diffusion model was proposed for analyzing the growth of Fe2B layers formed on the AISI 4140 steel during the pack-boriding process. This model was based on solving the mass-balance equations for the Fe2B/Fe interface to evaluate boron diffusion coefficients through the Fe2B layers in a temperature range of 1123?1273 K. The boride incubation time for the Fe2B phase was included in the present model. The suggested model was validated experimentally at a temperature of 1253 K for a treatment time of 5 h. Furthermore, the generated boride layers were analyzed with light microscopy, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis (XRD). In addition, a contour diagram was also proposed as a function of treatment time and temperature. On the basis of our experimental results, the boron activation energy for the AISI 4140 steel was found to be 189.24 kJ mol?1.