For more than 6 years, the automated ultrasonic and eddy-current systems for the inspection of railroad wheel sets, developed by Fraunhofer IZFP and Fraunhofer TEG, have been field-hardened through daily operation at various maintenance facilities of the Deutsche Bahn (DB). The testing stations are equipped with IZFP's multi-channel electronics, a modular PC integrated system operating inside 19" rack-mounted industrial computers. Special requirements for new installations of stationary systems (AURA) and underfloor testing stations (UFPE) called for the development of state-of-the-art miniaturized front-end ultrasonic and eddy-current test instrumentation. This innovation offers new dimensions for the concept and design of such systems, including features providing effortless maintenance of the inspection systems. Due to the small size of the electronic modules they can be placed in close proximity to the transducer assembly. High-speed networking techniques ensure the transfer of all the acquired digital ultrasonic and eddy-current data from the frontend modules to the workstation responsible for data acquisition and analysis. The new front-end technology is applied for the testing stations of the latest generation. One example is a system installed at the DB plant Krefeld, specifically designed for the ultrasonic testing of ICE train drive wheels. The transducer assembly for wheel rim and disk inspection includes hot-swap modules with integrated UT front-end modules adapted to inspect specific wheel disk configurations. A second example represents testing equipment operating at the Süddeutsche Rail Service GmbH, Kaiserslautern. Ultrasonic and eddy-current front-end modules are responsible for the inspection of the wheel rim of disassembled wheel sets of freight cars. In addition to the wheel rim the solid axle is inspected in the same test stand using GE's Phased Array system. Miniaturized front-end modules are also advantageous for the inspection with the wheel sets installed at the train. The concept of such an underfloor testing system is outlined

Previous standards for the manufacturing inspection of railroad wheels using ultrasound, such as UIC 812, have been replaced by new standards, for example EN 13262 and RD32.144-2000, both requiring ultrasonic testing in immersion technique. These new standards require the development of an ultrasonic technique for 100% coverage of the wheel rim and wheel hub, and in special cases for both straight and curved wheel disks. In order to encompass a large variety of railroad wheel designs, inspection and handling techniques should be capable of dealing with wheel diameters ranging from 600 mm to 1300 mm (23" to 51") at testing cycles from 1 to 4 minutes per wheel. The current requirement for the minimum detectable flaw size is DSR 1 mm (disc shape reflector, DSR, 1 mm diameter) for high-speed train wheels rims and DSR 2mm for all other wheel rims. The minimum detectable flaw size for all other wheel areas (hub and disk areas) is DSR 3 mm. To meet all these criteria, the Rail Wheel Inspection (RWI) System was developed by IZFP and their partners. The system consists of an ultrasonic testing sub-system, immersion tank and transportation/handling sub-systems. Test cycles of 1 minute per wheel require two immersion tanks and two transportation/handling subsystems. The ultrasonic sub-system features modular computer-aided 6 to 16- channel UT electronics (PCUS 11) to employ 6 to 16 ultrasonic transducers (the precise number is determined by the testing procedure). This presentation paper offers descriptions of, and results from three of these systems that have been integrated into manufacturing processes at German and Russian wheel manufacturers, and provides details on the following topics: Wheel rim inspection, single-tank immersion technique, 4 minutes inspection cycle per wheel (Bochum, Germany) Wheel rim, hub and disc inspection, single-tank immersion technique, 2 minutes inspection cycle per wheel (Ilsenburg, Germany) Wheel rim, hub and disc inspection, dual-tank immersion technique, 1 minute inspection cycle per wheel (Nishny-Tagil, Russia

KurzfassungRadsätze von Hochgeschwindigkeitszügen (ICE u.a.) sind während ihrer Lebensdauer einer hohen dynamischen Belastung ausgesetzt. Derzeit werden die Radsätze von ICE – Zügen etwa alle 250000 km einer zerstörungsfreien Prüfung im Bereich des Radkranzes und der Radscheibe unterzogen. Für eine neue Generation von europäischen Hochgeschwindigkeitszügen wird das zerstörungsfreie Prüfsystem »SUPRA« vorgestellt, mit dem sich Räder bei einer Überrollgeschwindigkeit von ca. 5 km/h prüfen lassen. Ein kostenintensiver Stillstand des Zuges während der zerstörungsfreien Werkstoffprüfung der Räder entfällt.

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