Prediction of One Stage Hot Radial Forging Force Using Response Surface Method

Radial forging is an open die forging process for converting ingot into the hollow and solid cylinders. Deformation in this process results from a large number of short strokes and high speed hammer blows on the workpiece. Because of maximum forging force per die is constant, determining of die force before process can prevent die damage and wastage of material. In this research a hot radial forging process is simulated thermo mechanically through 3D finite element method. The behaviour of material is considered as an elastic-visco-plastic. A mixture of coulomb law and constant limit shear is applied to simulate workpiece-die contact. As determination of radial forging force by simulation, is time consuming, so in this paper for prediction die force, response surface method (RSM) is used. RSM is the combination of mathematical and statistical techniques used in an empirical study of relationships and optimization, where several independent variables, influence a dependent variable or response. RSM, the relationships between the responses and the variables investigated is commonly approximated by polynomial functions, whilst the model parameters are obtained by a small number of experiments utilizing a design of experiment. In this paper four parameters such as die inlet angle, billet temperature, work piece feed rate and reduction used as input parameters and die force used as output parameter.