On the Development of Parametrical Water Quenching Heat Transfer Model Using Quenchometer and Its Validation for All Boiling Regimes

In the water quenching process of Aluminum 319, temperature drops rapidly from solutionizing temperatures, around 500°C, to water pool temperature. In this temperature range, the quenching process goes through three boiling regimes: film boiling, transition boiling, and nucleate boiling, before reducing to convection heat transfer. Each boiling regime has unique heat transfer characteristics governed by different physics. A common method to analyze the heat transfer rate in liquid quenching is the cooling curve analysis by quenchometer. Among several methodologies to characterize heat transfer rate, we have found successes in adapting a heat transfer framework based on Leidenfrost point (LFP), minimum heat flux (MHF), and critical heat flux (CHF) to develop a CFD model for quenching process simulation. The CFD model then can be used to calculate temperature histories as well as temperature profiles and the simulation results can be sent to FEA to predict thermal residual stress and distortion. Although the LFP, MHF, and CHF framework has been proven useful for the numerical simulation of water quenching process, these parameters are not constant and they have to be calibrated through experiments for each quenching condition. The objective of this paper is to parameterize the boiling model by quenching conditions such as water pool temperature. Then the predictive model is validated by experimental data obtained by quenchometers.