TY - CONF A1 - Schenk, Gottfried A1 - Brackrock, Daniel A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc A1 - Deutsch, W.A.K. A1 - Joswig, M. A1 - Maxam, K. A1 - Schuster, V. ED - Thompson, D.O. ED - Chimenti, D.E. T1 - Ultrasonic inspection system for automated round-bar-testing based on phased array technique N2 - Within a know-how transfer project funded by the government conventional ultrasonic technique was replaced by phased array technique for automated round-bar testing. Instead of applying a great number of conventional probes to achieve acceptable volume coverage we used curved linear arrays. The benefits of phased array technique such as programmable skew angles, beamforming and beam positions, led not only to a significant decrease in inspection time, but also the number of probes could be substantially reduced . Finally, the testing parameters for a large range of bar-diameters could be adapted by software control instead of time-consuming mechanical replacement. The probe-design was carried out by a proprietary modelling program. Both the theoretical calculations as well as the latter experimental verifications revealed significant advantages of curved arrays versus the planar types. A radial oriented probe offers perfect adaption to the cylindrical shape of the specimen allowing wide variations of the sound field. Thus beam direction, beam size and beam position could be optimized with respect to a minimum of inspection cycles, as inspections have to be executed in-line during the production. A number of laboratory tests were carried out on special test components. In order to achieve an optimal performance of the reference rod we implemented three different types of reference reflectors: (i) flat-bottom-holes with diameters of 0.8 mm and 1.2 mm, (ii) side-drilled-holes with a diameter of 0.7 mm for the detection of volumetric flaws, and (iii) notches with a depth of 0.2 mm and 0.5 mm for the detection of surfaceoriented defects. All laboratory tests were carried out with the COMPAS-XXL inspection system, a proprietary development of BAM. T2 - 36th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Kingston, RI, USA DA - 2009-07-26 KW - Ultrasonic testing KW - Phased array KW - Round bar testing PY - 2010 SN - 978-0-7354-0748-0 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings VL - 29 SP - 1 EP - 7 CY - Melville, NY AN - OPUS4-21817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schenk, Gottfried A1 - Brackrock, Daniel A1 - Boehm, Rainer A1 - Kreutzbruck, Marc A1 - Deutsch, W.A.K. A1 - Joswig, M. A1 - Maxam, K. A1 - Schuster, V. T1 - Untersuchungen zum Einfluss von Geometrie- und Temperaturabweichungen bei der Stangenprüfung mit Ultraschall-Gruppenstrahlertechnik N2 - Bei der automatisierten Prüfung von Stangen mit Ultraschall- Gruppenstrahlertechnik besteht grundsätzlich die Möglichkeit, Prüfkopfparameter wie Einschallwinkel, Fokustiefe und Schallbündelbreite programmgesteuert an sich verändernde Prüfbedingungen anzupassen. Zu diesen zählt die Temperatur des Koppelmediums (Wasser), die in einem Bereich von 10°C bis 50°C liegen kann, was zu unterschiedlichen Schallgeschwindigkeiten führt und den Einschallwinkel verändert. Mit der Folge, dass unter Umständen die geforderte 100%-Abdeckung des Prüfvolumens nicht mehr gewährleistet ist. Auch geometrische Abweichungen, wie sie durch die fertigungsbedingte Streuung des Prüflings gegeben sind, können Einfluss auf das Prüfergebnis nehmen. So führen Abweichungen vom idealen Geradheitszustand zu Fehlpositionierungen des Prüfkopfs, was wiederum Einfluss auf die Lage und Beschaffenheit des Schallbündels in der Stange hat. Ähnliches gilt für nicht vollkommen kreisförmig ausgebildete Stangendurchmesser, die unterschiedliche Schalleintrittsbedingungen bewirken und Abweichungen von den theoretisch ermittelten Werten zur Folge haben. Im Rahmen eines vom BMWi geförderten Forschungsvorhabens wurde der Einfluss dieser Parameter untersucht und ihre Auswirkungen für den Betrieb einer automatisierten Prüfanlage unter realen Betriebsbedingungen ermittelt. Dies betrifft vor allem den maximal möglichen Schallbündelversatz innerhalb des Arrays, der die Anzahl der erforderlichen Prüftakte bestimmt und damit die maximale Vorschubgeschwindigkeit des Prüflings. Des Weiteren werden Möglichkeiten zur programmgesteuerten Kompensation der untersuchten Temperatur- und Geometrieabweichungen durch eine flexible Anpassung der Gruppenstrahler- Prüfkopfparameter aufgezeigt. T2 - DGZfP-Jahrestagung 2010 CY - Erfurt, Deutschland DA - 2010-05-10 PY - 2010 SN - 978-3-940283-26-9 IS - DGZfP-BB 122 (Mi.4.A.1) SP - 1 EP - 8 CY - Berlin AN - OPUS4-21878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Brekow, Gerhard A1 - Kreutzbruck, Marc A1 - Boehm, Rainer A1 - Kitze, Jessica A1 - Eggers, H. A1 - Böwe, M. T1 - Using UT-SAFT for analysis of stress corrosion cracking N2 - Stress corrosion cracking is a transcrystalline or intercrystalline crack formation in materials which occurs under the influence of static tensile stress or residual stress and a specific aggressive medium such as chloride containing substances. This special sort of crack formation is involved in complex crack configurations, which may only insufficiently be captured by conventional ultrasonic probes with fixed angles of incidence. Only a number of different beam angles produce sufficient reflection to reconstruct the complete defect shape from measured ultrasonic data. The SAFT algorithm, which was recently successfully used in many industrial NDT-applications, is a promising tool for the reconstruction process. In addition, the combination of phased array technique and SAFT was developed in several projects by BAM, Berlin. Investigations using phased array equipment were performed to look into crack configurations in test blocks with different surface curvatures. UT-SAFT has been used for the analysis of spark-eroded notches simulating stress corrosion cracks at the thermo sleeve weld of a nozzle. For comparison, UT-SAFT has also been applied for the analysis of real reflectors at the same position in a nozzle used in a power plant, which was repaired later on. SAFT-scans received from reconstructed ultrasonic measurement data confirm the practical usefulness of the SAFTalgorithm developed by BAM. T2 - 8th International conference on NDE in relation to structural integrity for nuclear and pressurised components CY - Berlin, Germany DA - 2010-09-29 KW - Stress corrosion cracking KW - Real and simulated cracks KW - D-nozzle KW - Phased array technique KW - SAFT reconstruction PY - 2010 SN - 978-3-940283-30-6 IS - DGZfP-BB 125 (Th.2.B.1) SP - 1 EP - 10 CY - Berlin AN - OPUS4-23594 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -