The Research Of Straightening High-strength Steel Thin-plate Welding Deformation Based On Induction Heating

In the shipbuilding process,residual stress and deformation of parts will be generated due to welding,especially in the welding of thin plates.This is a common phenomenon,especially for high-strength steels.The traditional flame straightening usually use a flame to heat the steel plate with a large thickness,and the steel plate will be straighten by stress which generated by the temperature gradient.However,this method is not efficient for thin plates because of the low temperature gradient.As a new straightening measure,the sensor of induction heating generates a heating eddy current on the steel plate,so that the temperature of the concentrated heating zone rises rapidly.Compared with traditional flame straightening,induction heating is efficient and controllable.In the actual production and processing,the induction heating straightening is operated by experience,the heating parameters of the heater such as speed,length and so on cannot be determined accurately.For some structural deformation,the purpose of straightening is usually achieved through repeated processing.In some cases,reprocessing will be carried out,which will increase the working hours and seriously restrict the construction efficiency of ships.It is very important to study the relationship between the sheet deformation and the induction heating parameters.Establish the support vector machine(SVM)prediction model to guide induction heating straighten sheet deformation is helpful to predict deformation and optimize parameters of induction heating.Because the welding deformation is caused by residual stress,it is necessary to consider the residual stress in the thin plate.In this paper,after the butt welding finite element simulation model is established,the calculated results are compared with the experimental results in order to obtain accurate residual stress.Then,residual stress field is used as an initial boundary condition for induction heating analysis.The finite element model of electromagnetic,thermal and structural coupling of electromagnetic induction heating is further established,and the numerical simulation results are carried out.The induction heating parameters and straighten deformation amount are used as data sets to train the SVM model which is used to predict straightening value of different processing parameters.