Study On The Temperature Field Of U75V Heavy Rail By Electromagnetism Induction Heating

With the sustainable and rapid development of Chinese economy, the increasingrail traffic load on trains and rails have higher requirements. In order to meet the needof high—speed and over loading train’ running, heavy and seamless steel rail has beenincreasingly used. Heat—treatment was emphasized for its important role to qualifythe products of heavy rail, and induction quenching was one of the widely adoptedheating process quenching. With the continuous improvement of the accuracy, thesimulation of induction hardening becomes very important. The magnetic thermalcoupling for heavy rail, not only reflects the variation of temperature andorganizational fields in heavy rail electromagnetic induction heating, but also reducestest costs, saves time, and has certain guiding significance for the selection ofparameter in heavy rail quenching process. In this paper, the magnetic thermalcoupling simulation for U75V heavy rail was used finite element software ANSYS bybuilding a three—dimensional finite element model.Firstly, establish a three—dimensional induction heating model according toU75V heavy rail actual heating. In order to make the results more precise, incalculating process, various physical parameters of materials that changed bytemperatures. By changing the current density, frequency, and the air gap size for thecoupling simulation analysis, obtained the temperature fields of a different currentdensities, frequencies or air gaps, followed by its thermal insulation. And compare theresults of the analysis to be more optimized process parameters.Secondly, by loading the convection heat transfer coefficient between rail—endand media, the temperature field during wind—cooling process was numericalsimulated. According to the fitted cooling curve of key points, the cooling rate atphase transition point was calculated, and by comparing which with every criticalcooling rate, and testing results showed that the prediction was correct. In order tominimize the thermal stress produced during cooling, heavy rail would be temperedwith its own temperature and be cooled in air.This paper simulated rail—side’s induction heating, insulation, wind—coolingand air—cooling process for U75V, and the final cooling microstructures werecalculated based on the empirical formulation. In actual production, using APDLmethod can be applied to guide the selecting of various parameters, and had importantreference value on the choice of rail—side’s quenching parameters.