Rechnerischer Festigkeitsnachweis für korrosionsbeanspruchte Maschinenbauteile FKM Heft 303

Computational strength verification for machine components exposed to corrosion FKM 2009
Issue number 303
Project no. 278

Abstract:
Within the scope of this project, the knowledge available from freely accessible literature and from the work of the research center on the change in strength properties under complex mechanical-corrosive stress was condensed for the first time, evaluated in a closed manner and prepared for computational treatment, so that a link to the existing FKM guideline "Computational strength verification for mechanical engineering components" can be made.an estimation of the influence of corrosion on the fatigue properties of iron-based materials was determined using a closed evaluation approach. This was done on the basis of a regression calculation according to a potential growth law. The basis was a complete digitization of the Wöhler lines and test points from the literature, which made it possible to summarize and regress test data together with the help of classifications, groupings and influencing factors. The result was a tabular presentation of the corrosion reduction for iron-based materials according to material groups, media classes and influencing factors. In addition to a notch pre-factor to be determined and the component fatigue strength calculated according to the FKM guideline, the corrosion reduction parameters to be read from this table for the respective corrosion system are the input variables required to determine the corrosion fatigue strength according to a modified equation of the Wöhler line. The estimation of a stress corrosion cracking hazard (SCC) of corrosion systems was carried out on the basis of the creation of a step-by-step decision aid for the user, with which he can recognize and avoid critical material-environment systems. The possible influencing factors and problem solutions for the avoidance of corrosion risk were identified by breaking down the problems involved in the design of components and providing specific assistance. In particular, knowledge of the component conditions that are critical for stress corrosion cracking with regard to the material, the ambient conditions or the static load as well as the avoidance of such system conditions can be a valuable aid for the safe design of statically loaded components under the influence of corrosion. The objective of the research project has been achieved.
Scope of report:
87 p., 43 fig., 00 tab., 129 lit.Start of work:
01.08.2006End of work:
31.01.2009Supplier:
BMWi I AiF-Nr. 14854 NResearch center:
Institute of Materials Science, TU Darmstadt
Head: Prof. Dr.-lng. C. Berger, editor and author:
Dipl.-lng. R. Breining, chairman of the working group:
Dipl.-lng. J. Denk, Chairman of the FKM Board:
Dipl.-lng. H. Linn, LlNN HIGH THERM GmbH, Hirschbach