PSI - Issue 46

L. Lücker et al. / Procedia Structural Integrity 46 (2023) 94–98 Lukas Lücker / Structural Integrity Procedia 00 (2021) 000–000

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4. Summary and outlook The forming-induced ductile pre-damage in 16MnCrS5 steel specimen extracted from forward rod extrusion parts was evaluated qualitatively and non-destructively by electrical resistance using a newly developed experimental setup. The delta mode was applied in order to eliminate disturbance variables of thermoelectric offset and to enable sensitive and accurate measurements. The forming-induced damage level leads to differences in the electrical resistance measurements, while in three-point bending fatigue tests no difference could be detected. This may underline the sensitivity of the electrical measurement and needs further validation. In order to further reduce the scattering of electrical resistance measurements, parameters and contacting will be optimized in future investigations. In order to prove the influence of pre-damage on the fatigue strength, very high cycle fatigue (VHCF) tests are planned. Acknowledgments The authors gratefully acknowledge the funding by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG) for the subproject B01 within the Collaborative Research Center CRC/Transregio 188 “Damage-Controlled Forming Processes” (project no.: 278868966). The authors further thank the Institute for Forming Technology and Lightweight Construction (IUL) of TU Dortmund University (subproject A02) for the provision of components and analyses in the framework of an excellent scientific collaboration. References Tekkaya, A.E., Ben Khalifa, N., Hering, O., Meya, R., Myslicki, S., Walther, F., 2017. Forming-induced damage and its effects on product properties. CIRP Annals - Manufacturing Technology 66, 281–284. Lemaitre, J., 1985. A continuous damage mechanics model for ductile fracture. Journal of Engineering Materials and Technology 107, 83–89. Teschke, M., Rozo Vasquez, J., Lücker, L., Walther, F.: Characterization of damage evolution on hot flat rolled mild steel sheets by means of micromagnetic parameters and fatigue strength determination. Materials 13 (11), 2486 (2020) 1–19. Borsutzki, M., Thiessen, R., Altpeter, I., Dobmann, G., Tschuncky, R., Szielasko, K., 2010. Nondestructive characterisation of damage evolution in advanced high strength steels. 18th European Conference on Fracture: Fracture of Materials and Structures from Micro to Macro Scale 1–9. Tschuncky, R., Altpeter, I., Szielasko, K., 2016. Electromagnetic techniques for materials characterization. Materials Characterization Using Nondestructive Evaluation (NDE) Methods 225–262. Koch, A., Bonhage, M., Teschke, M., Lücker, L., Behrens, B.-A., Walther, F., 2020. Electrical resistance-based fatigue assessment and capability prediction of extrudates from recycled field-assisted sintered EN AW-6082 aluminium chips. Materials Characterization 169, 110644, 1–8. Hering, O., Dunlap, A., Tekkaya, A., Aretz, A., Schwedt, A., 2020. Characterization of damage in forward rod extruded parts. International Journal of Material Forming 13(6), 1003–1014. Samfaß, L., Baak, N., Meya, R., Hering, O., Tekkaya, A.E., Walther, F., 2020. Micro-magnetic damage characterization of bent and cold forged parts. Production Engineering Research and Development 14(1), 77–85.