The Influence of the Punch Shape and the Cutting Method on the Limit Strain in the Hole Expansion Test

Abstract:

The article presents a comparison of the hole-flange factors for four steel sheets which have different strength parameters. Three types of punches were applied in the research: cylindrical, spherical and conical. The holes in the samples were made with the use of the following cutting technologies: laser cutting, electrodischarge method using wire and punching. The coefficient of the hole expansion shows that the shape of the used tools has a great impact on the final diameter of the hole. The greatest enlargement of the diameter was obtained for the conical punch, a smaller enlargement for the spherical one and the smallest enlargement for the cylindrical punch. The results of the hole expansion tests using the conical punch diverge from the general rule saying that the greater the plastic deformation of the sheet metal during tensile tests, the more you can enlarge the hole before cracking appears.

• Periodical: Key Engineering Materials (Volume 716)
• Pages: 129-137
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.716.129
• Online since: October 2016
• Authors: Jakub Krawczyk*, Zbigniew Gronostajski, Sławomir Polak, Karol Jaśkiewicz, Władysław Chorzępa, Ireneusz Pęcak
• Keywords: AHSS Steel, HE Index, Hole Expansion Test

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