A Numerical and Experimental Study of Constrained Ironing Process as a Novel High Thickness Reduction Ironing Method

Constrained ironing is a new ironing technique with extra high thickness reduction for producing thin-walled cylindrical cups. In this study, the effects of constrained ironing process parameters such as die angle, thickness reduction ratio and friction coefficient were investigated using experimental and finite element (FE) methods. Also, the stress state in the deformation zone in the conventional and constrained ironing process was examined by FE simulation. The FEM results showed that increase in the ironing die angle caused to decrease the punch load. Also, the state of the stress was fully compressive in constrained ironing process while it was tensile in the conventional ironing method. The results showed that after the introduction of this new method, the hardness increased to about 85 Hv from the initial values of 25 HV.