Abstract
Many investigations have revealed the beneficial effect of mechanical surface hardening in combination with induced compressive residual stresses leading to improved fatigue strength. The benefit will be higher, the higher the quality of the weld is. On the other hand, methods like shot peening are useless if the weld toe profile is poor and the connected notch effect strong. Increased fatigue strength is then only possible after a post weld treatment which produces a smoother shape of the weld toe. Experiments reveal that methods which aim to increase the intensity of the penetration depth do not necessarily produce the best fatigue performance. High intensities of the mechanical surface treatments, especially in ductile aluminium alloys, may produce new geometrical defects which may work against the benefit of the deeper penetration depth of cold hardening and compressive residual stresses. A systematic evaluation of the results of improvement methods is possible with the help of the local fatigue strength concept, which compares the local strength properties and the local load stresses.
Literatur
[1] B.Müsgen: Komm. der Europ. Gemeinschaften, Technische Forschung Stahl, EUR 7634, 1982.Search in Google Scholar
[2] F.Haagensen, in: C. Nordhoek, J. de Back (Eds.), Steel in Marine Structures, Proc. 3nd Int. ECSC Offshore Conf. (SIMS '87), Delft, The Netherlands, June 15–18, 1987, S. 689–698, Elsevier Science Publishers B.V.Search in Google Scholar
[3] S.J.Maddox, S.Manthegi: IIW-Doc. XIII-2006-04, August 2004.Search in Google Scholar
[4] P.J.Haagensen: IIW-Doc. XIII-1748-98, August 1998.Search in Google Scholar
[5] C.M.Sonsino, C.Morgenstern, A.Hobbacher, F.Sorbo: IIW-Doc. XIII-2009-045, August 2004.Search in Google Scholar
[6] H.Wohlfahrt, P.Krull (Eds.): Mechanische Oberflächenbehandlungen: Grundlagen – Bauteileigenschaften – Anwendungen. WILEY-VCH-VerlagWeinheim2000.Search in Google Scholar
[7] J.Heeschen: Diss. 1986, Univ. Gh Kassel (1986).Search in Google Scholar
[8] T.Nitschke-Pagel, H.Wohlfahrt, in: L. Wagner (Ed.), Proc. of the 8th Int. Conf. on Shot Peening, Viley-VCH2003, S.360–366.Search in Google Scholar
[9] T.Nitschke-Pagel: Abschlußbericht zum Teilprojekt “Auswirkungen von Nachbehandlungsverfahren auf die Schwingfestigkeit lasergeschweißter Stumpfnähte“. Bericht LUFO II, Airbus Industries2003.Search in Google Scholar
[10] E.Macherauch, H.Wohlfahrt, in: D.Munz (Ed.), Ermüdungsverhalten metallischer Werkstoffe, DGM-Informationsgesellschaft Verlag, Oberursel1985, S. 237–283.Search in Google Scholar
[11] P.J.Haagensen: IIW-Doc. XIII-WG2-30. 08/1994.Search in Google Scholar
[12] T.Nitschke-Pagel, H.Wohlfahrt, in: DVM-Bericht 127, Dt. Verband für Materialforschung und -prüfung e.V., Berlin2000, S. 211–228.Search in Google Scholar
[13] Th.Nitschke-Pagel: in [6].Search in Google Scholar
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