University of Oulu

V Kesti et al 2022 IOP Conf. Ser.: Mater. Sci. Eng. 1238 012035,

An approach to describe edge ductility

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Author: Kesti, V.1; Folmerz, M.2; Vierelä, R.3;
Organizations: 1SSAB Europe, Raahe, Finland
2SSAB Europe, Borlänge, Sweden
3Lapland University of Applied Sciences, Kemi, Finland
4Materials and Mechanical Engineering, CASR, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 1.7 MB)
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Language: English
Published: IOP Publishing, 2022
Publish Date: 2022-06-16


One of the challenges of utilizing advanced high-strength steels is their limited ability to withstand the forming of cut edges. Large production quantities of parts often lead to mechanical punching/shearing processes in blank preparation, providing a challenging starting point for forming processes. The most commonly used edge ductility test is the ISO 16630 hole-expansion test to describe stretch-flangeability properties. However, this method has been widely criticized for its large-scatter, unreliable results and the fact that it covers only a certain stress-strain state of cut edge forming. In addition, it does not provide enough data to be reliably used in forming simulations to predict edge failures. This paper presents an approach to create a more comprehensive way of describing overall edge ductility. Multiple edge forming test methods coupled with digital image correlation (DIC) were selected in order to investigate different edge loading scenarios in both open and closed trim line forming situations. Data regarding limiting local strain before cracking was collected for several steel grades, and results are gathered in 2D and 3D "Edge FLC"-figures. Attempts to utilize these results for simulation purposes are also presented. Results indicate that this approach can be useful to evaluate overall edge forming limits.

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Series: IOP conference series. Materials science and engineering
ISSN: 1757-8981
ISSN-E: 1757-899X
ISSN-L: 1757-8981
Volume: 1238
Article number: 012035
DOI: 10.1088/1757-899x/1238/1/012035
Host publication: IOP Conference Series : Materials Science and Engineering
Host publication editor: Thuillier, Sandrine
Grolleau, Vincent
Lauren, Hervé
Conference: International Deep-Drawing Research Group Conference
Type of Publication: A4 Article in conference proceedings
Field of Science: 216 Materials engineering
Funding: Financial assistance of the Business Finland, projects ISA – Intelligent Steel Applications and FOSSA–Fossil-Free Steel Applications, are acknowledged.
Copyright information: © 2022 The Authors. Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.