J. B. Hernández-Morales, Universidad Nacional Autónoma de México, México D.F., Mexico; A. M. Dueñas-Pérez, M. Díaz-Cruz, Instituto Politécnico Nacional, México, Mexico
Fluidized bed technology has emerged as an attractive alternative to conventional quenching media. To provide with analytical tools to aid in further developing this process, a mathematical model to predict the microstructural response of a medium-carbon, low-alloy steel (AISI 4140) quenched in a fluidized bed has been developed and validated. The numerical solution was implemented using the finite-element method.
Several probes were quenched in a laboratory-scale fluidized bed reactor under various cooling conditions. The thermal responses at two radial positions within the probe were monitored during the quench to: 1) estimate the thermal boundary condition, and 2) validate the mathematical model. After the quench the probes were prepared for metallographic analysis and the as-quenched hardness was measured. The results of this characterization were used to further validate the mathematical model. A good agreement was observed between measured and model-predicted thermal response, phase distribution and hardness.
Summary: A mathematical model to predict the microstructural response of AISI 4140 steel probes quenched in a laboratory-scale fluidized bed reactor is described.
The model was validated by comparing the predicted thermal response, final phase distribution and hardness against the measured values. A good agreement was observed; thus, the model may be considered as validated.
