HEAT-TRANSFER EVALUATION OF IMPINGEMENT COOLING IN HOT-ROLLING OF SHAPED STEELS

The accuracy of mathematical modelling is strongly influenced by the boundary conditions assumed. A shape rolling mill was instrumented to provide on-line temperature measurements during hot rolling of steels. An inverse heat conduction technique was used to convert the measurement data to surface heat fluxes and heat transfer coefficients. The heat transfer coefficient or heat flux could then be used as the necessary boundary condition for the computation of temperature field in the entire roll and workpiece by means of conventional heat transfer analysis. The heat transfer phenomena involved and the influence of the major operating parameters on the heat transfer results have also been discussed. Finally, the paper has shown that the numerical evaluation procedure adopted has at least the same influence on the results as the accuracy of temperature sensors and the properness of experiment design.