The Couple-field Numerical Simulation Of Electro-slag Furnace Induction Hardening Based On ANSYS

With the rapid development of metallurgy industry, the use of ingot is becoming more and more common. Yet the electro-slag furnace is one of the main equipments which product ingots. Therefore, if the design of the electro-slag furnace is the main index that decides to the working environment. In the usage process of the electro-slag furnace, because of the alternative current reaching to 24000A, it creates a major alternative magnetic field in the surrounding of the electro-slag furnace. According to electromagnetism theory, alternative magnetic field would create induction electromotive force, which makes backset circulation creates a great deal of energy. It is called induction heating. A great deal of energy makes parts surface create severe transformation, therefore induction hardening numerical simulation is necessary. The numerical simulation can reflect the change laws for the electromagnetic field, eddy current and thermal field inside of the workpieces. The recent research on the coupling of electromagnetic and thermal field using the Finite Element Method (FEM) analysis has practical value in reducing testing cost, assisting in the design of the inductor and improving their technical parameters.In this paper, ANSYS/Multiphysics software from ANSYS Inc. is used to simulate induction hardening of the chucking appliance of the electro-slag furnace. The software allows engineers to simulate various physical phenomena using finite element analysis (FEA), including the interaction (coupling) between the various physical phenomena. In this simulation, electromagnetic-thermal coupling and thermal-stress coupling are used. In the calculation of induction hardening, firstly current and frequency are applied to the finite elements making up the electrical pole and graphite electrode, and an electromagnetic harmonic analysis is performed. The program calculates the electromagnetic field caused by the current, as well as the Joule heat at the surface of the chucking appliance and the resulting Joule heat. This is followed by a transient thermal analysis which calculated the temperature distribution in the chucking appliance due to the previously calculated joule heat. Since the electromagnetic properties of the chucking appliance are a function of temperature, the electromagnetic analysis needs to be repeated. Accounting for the change in material properties, this in turn causes a change in the electromagnetic field. So the transient thermal analysis also needs to be repeated. In this manner, several "loops" of electromagnetic and thermal analyses are performed to correctly predict induction heating of the electro-slag furnace. Then, the program calculates the chucking appliance appearance cooling temperature field and residual stress field. At last, the program still calculates the chucking appliance magnetic field and temperature field in loading magnetic shaded pole.