Abstract
The increasing use of hot-formed steels for structural components in lightweight construction requires solutions to create mounting points into the thin blank of high-strength steel. Compared to welding nuts, self-piercing nuts are often used due to advantages for the mechanical properties. The problems of setting these elements in hot-formed steels like 22MnB5 are high process forces and often limited undercuts, which are produced during the joining process. In this regard, the application of the self-piercing nut during the hot forming process of 22MnB5 is the focus of the investigation. The particular challenge is to find out the desired process parameter in a defined temperature window. Thus, the ductile austenitized 22MnB5 is exploited, while the local shape of the deformed blank in contact with the self-piercing nut is realized. A newly developed process enables insertion of the self-piercing nuts by different joining conditions. In order to evaluate the efficiency of the new process, various aspects are recorded. To achieve a successful hot forming process by a complete martensitic microstructure transformation, a minimum cooling rate of 27 K/s is provided. Furthermore, it has to be assured, that there is no thermal influence on the nut element, while the blank and the self-piercing nut are strongly heated. Otherwise, this can lead to a change in the strength class of the nut. For this purpose, hardness measurement is used to analyze the microstructure development. The mechanical behavior is described by torsion- and pull-out tests.
Similar content being viewed by others
References
Karbasian H, Tekkaya AE (2010) A review on hot stamping. J Mater Process Technol 210(15):2103–2118
N.N. (2013) phs-ultraform® - Der Maßstab für presshärtende Stähle, ThyssenKrupp Steel Europe AG, Broschüre (in German)
N.N. (2012) Warmumformung im Automobilbau; Verfahren, Werkstoffe, Oberflächen; ThyssenKrupp Steel Europe AG, Süddeutscher Verlag onpact, München, Die Bibliothek der Technik Band 348 (in German)
Manzenreiter T (2013) Widerstandspunktschweißen als Methode zur Charakterisierung verzinkter presshärtender Stähle für die direkte Warmumformung, Tagungsband, 22. DVS-Sondertagung Widerstandsschweißen 2013, Duisburg, pp 91-97 (in German)
Hahn O, Füssel U, Schübeler C, Kalich J (2010) Mechanisches Fügen pressgehärteter Vergütungsstähle. Final report on the research project P 762, Forschungsvereinigung Stahlanwendung e. V., Düsseldorf (in German)
Humpert R (2010) Neuartige Bolzen für Karosseriebauteile. Tagungsband 30, EFB-Kolloquium, Blechverarbeitung, ISBN 978-3-86776-343-1, Bad Boll (in German)
Wesling V, Reiter R, Knauber A, Klier R (2008) Neue Entwicklungen beim Hülsenschweißen mit magnetisch bewegtem Lichtbogen auf konturierten Oberflächen. Tagungsband, Große Schweißtechnische Tagung 2008, Dresden (in German)
Li D, Chrysanthou A, Patel I, Williams G (2017) Self-piercing riveting- a review. Int J Adv Manuf Technol 92:1777–1824
Haque R (2018) Quality of self-piercing riveting (SPR) joints from cross-sectional perspective: a review. Arch Civil Mech Eng 18:83–93
Handge L (2017) Neues RND light Nietmutternsystem von Profil Verbindungstechnik: Gewichts- und Kosten-Diät, http://profil-verbindungs-technik.de/de/report.php?id=4. Accessed 22 February 2017 (in German)
N.N. (2007) Untersuchungen zum Anschweißen von Widerstandsschweißmuttern an Bleche aus höher- bis höchstfesten Werkstoffen; Final report on the research project AiF-No. 14.435 N, DVS-No. 04.039, Schweißtechnische Lehr- und Versuchsanstalt SLV München - Niederlassung der GSI mbH (in German)
Choi H-S, Park G-H, Lim W-S, Kim B-M (2011) Evaluation of weldability for resistance spot welded single-lap joint between GA780DP and hot-stamped 22MnB5 steel sheets. J Mech Sci Technol 25 (6): pp 1543–1550
RIBE Werknorm WN 20330 (2015) RIFAST Stanzmutter STM. Richard Bergner Verbindungstechnik GmbH & Co. KG, Schwabach (in German)
EN ISO 898-2 (2012) Mechanical properties of fasteners made of carbon steel and alloy steel – Part 2: nuts with specified property classes – coarse thread and fine pitch thread
Merklein M, Lechler J (2006) Investigation of the thermo-mechanical properties of hot stamping steels, J Mater Process Technol, 177, 452, 455
Vibrans V (2016) Induktive Erwärmung von Formplatinen für die Warmumformung, Doctoral thesis, Technische Universität Chemnitz (in German)
Behrens B-A, Bouguecha A, Gaebel C M, Moritz J, Schrödter J (2014) Hot stamping of load adjusted structural parts, 11th International Conference on Technology of Plasticity (ICTP), Nagoya (Japan)
Funding
In this paper, selected results of the funded research projects IGF No.: 18483N (EFB No.: 01/114) were presented. The IGF project IGF No.: 18483N (EFB No.: 01/114) of the Europäischen Forschungsgesellschaft für Blechverarbeitung e. V. was promoted through the AiF under the program for the promotion of joint industrial research and development (IGF) by the Federal Ministry of Economics and Energy due to a resolution of the German Bundestag.
Author information
Authors and Affiliations
Corresponding author
Additional information
Recommended for publication by Commission III - Resistance Welding, Solid State Welding, and Allied Joining Process
Rights and permissions
About this article
Cite this article
Meyer, S., Meschut, G., Vogt, H. et al. Application of self-piercing nuts during hot forming of 22MNB5. Weld World 63, 565–574 (2019). https://doi.org/10.1007/s40194-018-00688-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s40194-018-00688-8