Research objectives and content
Materials subjected to cyclic loading experience a change in the microstructure, which may affect the service life.
The scope of the project is to increase the knowledge on the evaluation of the residual fatigue life time of austenitic stainless steels by characterization of the microstructure with defined fatigue strain and residual life time (microstructure, mechanical and physical properties) and qualification of non-destructive testing methods, which are sensitive to changes in properties and are useful for on-site application. The results shall show - the correlation between fatigue strain with different characteristics (low-high cycle fatigue) and the changes in the microstructure and - the sensitivity of different ndt-methods to follow the changes in the microstructure and to evaluate the usage factor.
Training content (objective, benefit and expected impact)
Within the scope of the research work the applicant shall link the results from mechanical fatigue testing with the changes in the macro- and microstructure of the austenitic stainless material. In addition to the already existing knowledge on mechanical and fatigue testing, the applicant will be trained for the methodologies of the examination of the macro- and microstructure by optical, scanning and transmission electron microscopy (TEM) and nondestructive test methods. The impact of the work will be on the application of the analytical transmission electron microscopy and nondestructive testing methods in the host laboratory. Links with industry / industrial relevance (22)
The evaluation of the usage factor of components with possible fatigue strain during service is of great importance for the responsible operators of industrial plants (e.g. power plants, chemical industry, ...) with respect to problems arising from plant aging management, cost optimized preventive maintenance, and failure prevention.