A comparative study of temperature-dependent interfacial heat transfer coefficient prediction methods for 22MnB5 steel in spray quenching process

Abstract

Abstract The temperature-dependent interfacial heat transfer coefficient (IHTC) is an essential thermo-physical parameter between the heat treatable 22MnB5 boron steel and spray medium to assess heat transfer intensity and the temperature distribution, which could consequently affect the microstructure and mechanical property distribution of the material after spray quenching. Numerous prediction approaches for IHTC in quenching process have been extensively developed, and it is essential to compare them to choose the most suitable method for spray quenching applications. In the present study, the temperature distribution and characteristic of boiling heat transfer on 22MnB5 hot steel blank in spray quenching are investigated. The temperature-dependent IHTC curve in spray quenching process is calculated by five different numerical algorithms, including the Heat Balance Method (HBM), the Revised Heat Balance Method (R-HBM), the Beck s non-linear Estimation Method (BEM), the Finite-element Inverse Optimization Method (FIOM) and the Finite-element Optimization Method (FOM), and calculation accuracy of the above methods are discussed in detail. Besides, the ‘calculated’ IHTCs are introduced into the CFD model as the boundary conditions to predict the internal temperature distribution of the blank, and further compared with the experimental temperature profiles. It is concluded that the BEM owns the best calculating accuracy and efficiency between solid-fluid interfaces in spray quenching, and the internal temperature distribution prediction with IHTCs based on the BEM has the highest anastomosis degree with the real temperature.