The Study Of Line Heating Forming By Moveable Induction Heating Of The Steel Plate

In shipyards, the gas flame(Oxy-Acetylene) is usually used as a heating source to form the double curvatures shell plate. The technology of line heating takes advantage of the principle of expansion and contraction which makes the steel produce the residual plastic deformation achieving the purpose of steel bending deformation. Gas flame heating source has drawbacks such as low heating efficiency, poor repeatability, bad ability in automatic operation, while induction heating has its unique advantages in above aspects. With the development of induction heating technology, more and more scholars pay their attentions in induction heating technology.In order to realize the automatic forming of double curvature of hull plate by induction heating, achieving the mathematical model of induction process parameters and steel deformaion. Aiming at the problem of line heating technology by moveable induction heating, based on ansys software, adopted the technology of nodes coupling constraint, a coupled electromagnetic, thermal and structural model for numerical analysis of induction heating including the inductor moving relative to the steel plate is built, the validity of the numerical model is verified by comparison of numerical and experimental values. Meanwhile the temperature distribution and deformation mechanism of multi-field coupled conditions are studied.Then, in the technology study of pillow plate by moveable induction heating, in order to overcome the bad effect of the end effect on the edge deformation, the forming technical methods by moving the inductor out of plate edge and triangle heating are presented based on pillow plate respectively. The two heating technical methods take advantage of the expansion eddy current under the edge effect increasing the heating area of plate edge, so that the value of transverse shrinkage in plate edge is improved. The experimental value and numerical data both prove the fact that the two heating methods can effectively reduce the bad effect of edge effect on edge deformation and satisfy the forming requirements of pillow plate in shipyards, in the technology study of saddle plate by moveable induction heating, a coupled electromagnetic-thermal-structural model of saddle plate is presented. Meanwhile the eddy current characteristics and deformation distribution are analysed in the process of saddle plate induction heating. Finally, in order to study the forming technology of double curvature plate by moveable induction heating, based on the moveable induction heating numerical models of pillow plate and saddle plate, introducing the model of heating area, the relationship between heating area characteristic parameters and process parameters are built. Meanwhile, the deformation mathematical models of pillow plate and saddle plate are presented, the function relationship between transverse shrinkage and heating area characteristic parameters is built. So that based the on heating area characteristic parameters, we attain the mathematical model between transverse shrinkage and process parameters. The results lay the foundations for the establishment of the database of process parameters by the moveable induction heating for rolled plates.