In Chapter 16, the quenching medium analyzed was air. When water, oil and other similar mediums are used for quenching, heat transfer gets more complicated because the quenching medium goes into different heat transfer regimes, such as film boiling, transition between film boiling and nucleate boiling, nucleate boiling, and free convection, as the surface temperature of the material being quenched decreases.

Heat transfer in the boiling regime depends on material surface, quenching medium and material surface combination, and on the quenching medium's saturated liquid and vapor thermophysical characteristics. The best way to achieve heat transfer coefficients for boiling heat transfer in a quenching process is by experimental measurements (see Reference by Lee, W. J., Kim, Y. and, E. D. Case [12]).