An investigation on the damage of AISI-1045 and AISI-1025 steels in fine-blanking with negative clearance

The technical process of fine-blanking with negative clearance is introduced in this paper. Under the guidance of the Cockcroft and Latham fracture criteria, possible damage and fracture in the blanking process are simulated with FEM code DEFORM-2D. The quality differences between the conventional blanking and negative clearance blanking are discovered by computer simulation of AISI-1045 steel, as well as the effects caused by the material plasticity on blanking quality. The punch and die radii influence the blanking damage, and the appropriate values of the punch and die radii are determined. In addition, the following conclusions are obtained: the quality of negative clearance blanking is better than that of conventional blanking; and the better material plasticity, the better blanking quality. Final results of the FEM simulation agree with experimental data, which will provide reference for the engineering practice.