Investigation of the influence of loading direction after pre-forming on the formability and mechanical properties of DP600

Investigation of the influence of loading direction after pre-forming on the formability and mechanical properties of DP600

NORZ Roman, VALENCIA Fabuer R., VITZTHUM Simon, UNGUREANU Bogdan, GERKE Steffen, BRÜNIG Michael, VOLK Wolfram

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Abstract. The material behaviour after non-proportional strain paths is subject of numerous current investigations. These investigations show that in addition to the stress state, a change in the direction of loading also has a significant influence on the material behaviour. In this work, the influence of non-proportional strain paths on the mechanical properties such as tensile strength, uniform strain, elongation at fracture and yield strength as well as the influence on formability is determined. For this purpose, a dual-phase steel CR330Y590-DP, with a thickness of 0.8 mm, is investigated in more detail. The material is pre-strained to different strain values and then further examined with Nakajima and tensile tests. The influence of the loading direction is determined by five different post-strain directions (0°, 22,5°, 45°, 67.5°and 90°) to the initial pre-strain direction. In addition to the method according to the standard, the yield strength is determined by a temperature-dependent determination method, which is based on the thermoelastic effect. This method has already been qualified for simple uniaxial tensile tests and a relation to the microstructural behaviour was proven. Thus, it provides valuable conclusions on the microstructural behavior for the tests performed within this study with a change in the loading direction.

Keywords
Non-Proportional Load Paths, Cross-Loading, Onset of Yielding, Formability

Published online 4/19/2023, 8 pages
Copyright © 2023 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: NORZ Roman, VALENCIA Fabuer R., VITZTHUM Simon, UNGUREANU Bogdan, GERKE Steffen, BRÜNIG Michael, VOLK Wolfram, Investigation of the influence of loading direction after pre-forming on the formability and mechanical properties of DP600, Materials Research Proceedings, Vol. 28, pp 747-754, 2023

DOI: https://doi.org/10.21741/9781644902479-81

The article was published as article 81 of the book Material Forming

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

References
[1] D. Hérault, S. Thuillier, S.-Y. Lee, P.-Y. Manach, F. Barlat, Calibration of a strain path change model for a dual phase steel, Int. J. Mech. Sci. 194 (2021) 106217. https://doi.org/10.1016/j.ijmecsci.2020.106217.
[2] R. Larsson, O. Björklund, L. Nilsson, K. Simonsson, A study of high strength steels undergoing non-linear strain paths—Experiments and modelling, J. Mater. Process. Technol. 211 (2011) 122-132. https://doi.org/10.1016/j.jmatprotec.2010.09.004
[3] J. Liao, J.A. Sousa, A.B. Lopes, X. Xue, F. Barlat, A.B. Pereira, Mechanical, microstructural behaviour and modelling of dual phase steels under complex deformation paths, Int. J. Plast. 93 (2017) 269-290. https://doi.org/10.1016/j.ijplas.2016.03.010
[4] V. Tarigopula, O.S. Hopperstad, M. Langseth, A.H. Clausen, Elastic-plastic behaviour of dual-phase, high-strength steel under strain-path changes, European Journal of Mechanics – A/Solids 27 (2008) 764-782. https://doi.org/10.1016/j.euromechsol.2008.01.002
[5] F. Barlat, G. Vincze, J.J. Grácio, M.-G. Lee, E.F. Rauch, C.N. Tomé, Enhancements of homogenous anisotropic hardening model and application to mild and dual-phase steels, Int. J. Plast. 58 (2014) 201-218. https://doi.org/10.1016/j.ijplas.2013.11.002
[6] H.Y. Yu, J.Y. Shen, Evolution of mechanical properties for a dual-phase steel subjected to different loading paths, Mater. Des. 63 (2014) 412-418. https://doi.org/10.1016/j.matdes.2014.06.003
[7] A. Weinschenk, W. Volk, FEA-based development of a new tool for systematic experimental validation of nonlinear strain paths and design of test specimens, Penang, Malaysia, Author(s), 2017, pp. 20009.
[8] W. Volk, R. Norz, M. Eder, H. Hoffmann, Influence of non-proportional load paths and change in loading direction on the failure mode of sheet metals, CIRP Annals 69 (2020) 273-276. https://doi.org/10.1016/j.cirp.2020.03.009
[9] R. Norz, S. Vitzthum, W. Volk, Failure behaviour of various pre-formed steel sheets with respect to the mechanical grain boundary properties, Int. J. Mater. Form. 15 (2022) 1215. https://doi.org/10.1007/s12289-022-01700-9
[10] S. Vitzthum, J. Rebelo Kornmeier, M. Hofmann, M. Gruber, E. Maawad, A.C. Batista, C. Hartmann, W. Volk, In-situ analysis of the thermoelastic effect and its relation to the onset of yielding of low carbon steel, Mater. Des. 219 (2022) 110753. https://doi.org/10.1016/j.matdes.2022.110753
[11] W. Volk, P. Hora, New algorithm for a robust user-independent evaluation of beginning instability for the experimental FLC determination, Int. J. Mater. Form. 4 (2011) 339-346. https://doi.org/10.1007/s12289-010-1012-9
[12] R. Norz, F.R. Valencia, S. Gerke, M. Brünig, W. Volk, Experiments on forming behaviour of the aluminium alloy AA6016, IOP Conf. Ser.: Mater. Sci. Eng. 1238 (2022) 12023. https://doi.org/10.1088/1757-899X/1238/1/012023
[13] E.E. Aşık, E.S. Perdahcıoğlu, A.H. van den Boogaard, Microscopic investigation of damage mechanisms and anisotropic evolution of damage in DP600, Mater. Sci. Eng. A 739 (2019) 348-356. https://doi.org/10.1016/j.msea.2018.10.018
[14] G. Gerstein, H.-B. Besserer, F. Nürnberger, L.A. Barrales-Mora, L.S. Shvindlerman, Y. Estrin, H.J. Maier, Formation and growth of voids in dual-phase steel at microscale and nanoscale levels, J. Mater. Sci. 52 (2017) 4234–4243. https://doi.org/10.1007/s10853-016-0678-x
[15] E. Maire, O. Bouaziz, M. Di Michiel, C. Verdu, Initiation and growth of damage in a dual-phase steel observed by X-ray microtomography, Acta Mater. 56 (2008) 4954-4964. https://doi.org/10.1016/j.actamat.2008.06.015