The issue of low resistance of punches when heading of sunk screw made of ferrite-pearlite steels

Abstract

The causes are investigated and the types of punches wear during extrusion of a cruciform slot in screws with countersunk head from ferritic-pearlite class steels, in particular, 16KhSN steel, are evaluated. The research methodology included two simulations of the M5 screw landing process using the DEFORM-3D software package. In the first simulation, using a generalized curve of the hardening of the material of the deformable workpiece, its stress state on the contact surface with the punch is determined. The obtained values were set in the form of a load on the punch when determining its stress state. The second simulation was carried out using the hardening curve of the punch material. The information obtained on the magnitude and distribution of stresses in the forming profile of the punch made it possible to draw a conclusion about the types of wear that are defined as loss of profile geometry and fatigue failure.