Objetivo Development of a methodology to identify and quantify the microstructural defect state in those components which determine the lifetime and performance of structures in industrial service for example power industry, leading to the formulation of codes for lifetime prediction and design. Progress to end 1990 Equipment New creep machines were installed and the data acquisition system has been changed for a better on-line evaluation of creep tests. The installation of a graphic workstation for the support of the theoretical part of the program has been performed. Experiments Creep behaviour with interruptions during tertiary creep has been examined on a Mn-Cr austenitic steel (AMCR 0033). Ultrasonic velocity measurements have been performed on AMCR 0033, the ferritic steels 13CrM044, 14MoV63, 10CrMo910 within COST 501 WPS and on Alloy 800H tubular specimens from Petten, in order to get information on the actual creep damage. For comparison, the microstructural defects due to creep were quantitatively determined by metallographic examination. In AMCR 0033, significant damage by microcracking of grain-boundaries during tertiary creep was observed. Modelling Material models based on a distribution of aligned cracks in a continuum were successfully applied for the description of the elastic and time-dependent inelastic behaviour. Statistical considerations of microcrack distribution led to a relation between damage parameters determined by metallographic and non-destructive ultrasonic measurements. External relations Participation in the COST-501 WP5, cooperation with KFA Julich (Inst.fur Reaktorwerkstoffe),Univ. Karlsruhe Inst. fur Zuverlassigkeit und Schadenskunde im Maschinenbau),Univ. of Sarajevo (elaboration of a joint research project).The results have been reported on a JUTAM-Symposium and two international conferences. A paper concerning finite element methods has been published. Detailed description of work foreseen in 1991 (expected results) Continuation of creep testing on austenitic steels and damage determination by ultrasonic (US) and metallographic methods. Improvement of metallographic examinations using image processors. Development of a programme for computer aided assessment of damage in structures and development of software for modelling of time-dependent inelastic behaviour. Participation in COST 501 WP 5. Creep tests on the oxide dispersion strengthened superalloy MA 6000 and studies of the damage mechanisms leading to fracture. Investigation of fatigue properties of surface treated aluminium alloys in collaboration with the Universities of Mostar and Sarajevo. Short description of evolution of work in 1992 Continuation of the work described above with particular emphasis on investigations in the ODS superalloys and fatigue problems in surface treated aluminium alloys. Programa(s) JRC-ADVMAT 1C - Specific research programmes (EEC) to be implemented by the Joint Research Centre - Advanced materials -, 1988-1991 Tema(s) Data not available Convocatoria de propuestas Data not available Régimen de financiación Data not available Coordinador Joint Research Centre (JRC) Aportación de la UE Sin datos Dirección 21020 Ispra Italia Ver en el mapa Coste total Sin datos
