Plastic deformation analysis of low-carbon steel due to metal hole punching using coated and uncoated tools

this paper presents subsurface hardening results of the low-carbon steel plate, deformed under industrial test conditions by punches manufactured in quenched and tempered aisi d2 steel, with and without tin coating. the punches are 12o double shear angle shaped. a longer tool life was obtained in tools with tin coatings applied by physical vapor deposition (pvd) process. the depth of hardened layer generated through punching was different for the work piece and slug. in the workpieces, this layer was about 1.5 mm wide, whereas in the slugs no hardness stabilization values were observed up to 4 mm. moreover, the presence of the tin coating did not affect the subsurface hardening produced by punching. the results were discussed regarding the wear mechanisms and the role of tin coating at the interface. therefore, the thermal effects were not relevant during the punching tests.