THE IMPACT OF SHEAR GAP SIZE ON THE QUALITY OF THE SHEARED SURFACE IN ELECTRICAL STEEL SHEET BLANKING

Abstract

The quality of the sheared surface when blanking, also known as die-cutting, is the result of several factors. Based on current knowledge about blanking, the following technological parameters – shear gap size, blunting of the shearing tool, lubrication in the shearing process, and deformation rate – can be considered as decisive parameters on the quality of the sheared surface. The main material characteristics include yield strength, tensile strength, ductility, and ferrite grain size. The paper is focused on the influence of the shear gap on the quality of the shear surface of electrical sheets with different chemical composition and different mechanical properties. The quality of the cutting surface was characterized by the size of the plastic cutting area. The relationships between the size of the shear gap, which ranged from 1 to 7% of the thickness of the cut material and the size of the plastic shear area, were evaluated and measured macroscopically.