Finite Element Simulation And Experimental Study On The Disc Slitting Process Of Galvanized Steel Sheet

The rapid development of household appliances, automobiles, IT and metal products industry promotes tremendous changes of processing theory, the equipment and quality requirements of metal products industry. The accuracy requirement of sheet metal and its products is becoming higher and higher. Slitting the wide sheet metal into the desired-width strip is the foundation for the production of precision metal products, therefore, the requirement of disc precision slitting for sheet metal is also rising. In order to deeply understand the process mechanism of disc slitting, optimize the processing parameters and control the slitting quality, the machining process of the traditional disc slitting and the plastic shearing-oppression separation precision slitting for galvanized steel sheet were simulated by using the DEFORM finite element analysis software, and the slitting experiment was conducted to verify the simulation results. Then the deformation and fracture process of the sheet, the surface morphology and the shearing force were analyzed.Based on the principle of disc slitting process for sheet metal, a3D model of the disc slitting for galvanized steel sheet was established by using the DEFORM software. The deformation and fracture of the sheet and the change of material effective stress were analyzed. The surface morphology of numerical simulation is in good agreement with the actual result. The plastic flow law of sheet metal was thoroughly studied through metallographic structure of material and the equivalent strain state. The material near the disc cutter blade has an obvious plastic flow, and the plastic deformation degree increases with the increasing of cut depth. The curve of shearing force was obtained and it well matched with the change rule in slitting process. Compared with the theoretical calculation results, the simulation result is reliable and the finite element analysis method can provide a reference for the calculation of shearing force. As the axial clearance increases, the shearing force and axial force gradually decreases. With the increase of the radial overlap, the shearing force decreases but the axial force increases gradually.Aiming at the disc slitting process of sheet metal、a smooth and burr-free slitting surface can be obtained by using the plastic shearing-oppression separation precision slitting technology. Based on the experiments of the burr-free precision slitting, a FEM model is established by using the DEFORM-2D software. The deformation of the galvanized steel sheet and the formation of the slitting surface morphology are analyzed by the metallographic structure and the hydrostatic stress in the slitting process. The numerical simulation results are in good agreement with the experimental results. The influence of the radial clearance and axial clearance between the two disc cutters on the slitting surface quality is studied. The results indicate that the best slitting surface can be obtained when the axial clearance is determined and the value of radial clearance is20%of the sheet thickness. The plastic shearing-oppression separation technology can be used only when the radial clearance is less than2.5%of the sheet thickness. The axial clearance does not have an obvious influence on the slitting surface in a reasonable range. The work hardening phenomenon of material can be produced in the burr-free precision slitting process. It is found that the degree and depth of the hardening in the fracture area is largest, but the hardening degree of two rollover area is much smaller. Compared with the traditional slitting process, the shearing force and axial force in the burr-free precision slitting process increase significantly.