Analysis of the Influence of Blanking Clearance on the Wear of the Punch, the Change of the Burr Size and the Geometry of the Hook Blanked in the Hardened Steel Sheet

Jacek Mucha; Jacek Tutak

doi:10.3390/ma12081261

Analysis of the Influence of Blanking Clearance on the Wear of the Punch, the Change of the Burr Size and the Geometry of the Hook Blanked in the Hardened Steel Sheet

Materials (Basel). 2019 Apr 17;12(8):1261. doi: 10.3390/ma12081261.

Authors

Jacek Mucha¹, Jacek Tutak²

Affiliations

¹ The Faculty of Mechanical Engineering and Aeronautics, Department of Mechanical Engineering, Rzeszów University of Technology, Al. Powstańców Warszawy 8, 35-959 Rzeszów, Poland. j_mucha@prz.edu.pl.
² The Faculty of Mechanical Engineering and Aeronautics, Department of Applied Mechanics and Robotics, Rzeszów University of Technology, Al. Powstańców Warszawy 8, 35-959 Rzeszów, Poland. tutak.j@prz.edu.pl.

Abstract

In this thesis, the results of an experimental analysis of blanking angled hooks with a punch of a sloping face in a thin steel sheet with a hardness of 55 HRC are presented. The blanking punch was made of K340 cold-work tool steel. Tests were carried out for three values of clearance, 5%, 10%, and 15% of sheet thickness. The results of the analysis of the influence of the number of cuts made by the punch on the growth of the burr at the sheet edge were presented. Moreover, the influences of the clearance on the initial values of burr (b_h), deflection (H_b), and the bending radius (R_b) of the hook have been shown. The influence of the friction path on the intensity of degradation of working surfaces and the blanking edges of the punch was also demonstrated. The obtained results allow the selection of the proper clearance and new tool materials for blanking blades working in particularly difficult tribological conditions.

Keywords: blanking; burr height; damage of the punch; sheet C45; sloping face of the punch.