PSI - Issue 18

Nikolas Baak et al. / Procedia Structural Integrity 18 (2019) 274–279 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Summary and outlook Micro-magnetic analysis is a powerful tool to characterize the material degradation dependent on fatigue load. Even in cases were established instrumentations like plastic strain amplitude measurements can’t differentiate, micro magnetic analysis is capable to detect a variety of process- and deformation-induced material reactions. It was also shown that the obtained parameter need an extensive interpretation on a microstructural level. Changes in micro magnetic parameters can be traced down to a diversity of material properties and microstructural features. In upcoming studies an extensive characterization of the material parameters and the microstructure of the deep drilled specimens and their development throughout the fatigue tests should be done. With this examinations, a separation of fatigue induced changes of the microstructure and the material properties can be done and allow an allocation to resulting micro-magnetic measurements. Acknowledgements The project “Investigations on the influence of machining and sulphur content on the fatigue strength of the quenched and tempered steel 42CrMo4+QT” was funded by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) – project number 320296624. Baak, N., Schaldach, F., Nickel, J., Biermann, D., Walther, F., 2018. Barkhausen noise assessment of the surface conditions due to deep hole drilling and their influence on the fatigue behaviour of AISI 4140. Metals 8, 720. Baak, N.; Garlich, M.; Schmiedt, A.; Bambach, M.; Walther, F., 2017. Characterization of residual stresses in austenitic disc springs induced by martensite formation during incremental forming using micromagnetic methods. Materials Testing 59, 309–314. Moorthy, V.; Shaw, B.A.; Hopkins, P., 2016. Surface and subsurface stress evaluation in case-carburised steel using high and low frequency magnetic Barkhausen emission measurements. Journal of magnetism and magnetic materials, 229, 362–375. Nickel, J.; Baak, N.; Biermann, D.; Walther, F., 2018. Influence of the deep hole drilling process and sulphur content on the fatigue strength of AISI 4140 steel components. Procedia CIRP 71, 209-214. Oevermann, T.; Saalfeld, S.; Niendorf, T.; Scholtes, B., 2017. Materials and process engineering aspects of warm deep rolling. International Journal of microstrucre and materials properties 12 (3/4), 230–238. Pfleghar, F., 1974. Kräfte an Schneide und Führungsleisten von Enlippen-Tiefbohrwerkzeugen. Werkzeugmaschine international 6, 51-56. Saalfeld, S.; Oevermann, T.; Niendorf, T.; Scholtes, B., 2019. Consequences of deep rolling on the fatigue behavior of steel SAE 1045 at high loading amplitudes. International Journal of fatigue 118, 192–201. Santa-aho, S.; Vippola, M.; Sorsa, A.; Leiviskä, K.; Lindgren, M.; Lepistö, T., 2012. Utilization of Barkhausen noise magnetizing sweeps for case depth detection from hardened steel. NDT&E International 52, 95–102. Sakuma, K., Taguchi, K., Katsuki, K., Takeyama, H., 1981. Self-guiding axtion of deep-hole drilling tools. CIRP Annals 30(1), 311-315. Starke, P., Walther, F., Eifler, D., 2018. Model-based correlation between change of electrical resistance and change of dislocation density of fatigued-loaded ICE R7 wheel steel specimens. Materials Testing 60, 7-8, 669-677. Vormwald, M.; Schlitzer, T; Panic, D.; Beier, H., 2018. Fatigue strength of autofrettaged diesel injection system components under elevated temperature. International Journal of Fatigue 113, 428-437. References