Modeling of the Growth Kinetics of Boride Layers during the Diffusion Annealing Process

Resumo

In the current work, a diffusion model was suggested to estimate the boron activation energies for FeB and Fe₂B layers on the gas-borided Armco iron at temperatures of 1073, 1173, and 1273 K for a treatment time varying between 1.33 and 4 h. This model takes into account the effect of boride incubation times during the formation of the FeB and Fe₂B phases. The mass balance equations were reformulated to describe the evolution of boride layers after applying the diffusion annealing process. In addition, the time needed to completely dissolve the FeB phase in the boride layer was also predicted. This predicted time was influenced by the boriding parameters during the diffusion annealing process.