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Ultrasonic Phased Array techniques are applied in medical and technical fields for many years now. Due to increasing computer performances nowadays also advanced imaging techniques can be applied, delivering higher image resolutions compared to traditional sector scans and linear scans which are only based on focused sound beams. The total focusing method (TFM) is a signal processing algorithm using data acquired in full matrix capture mode (FMC). All computations are achieved at a refresh rate up to 30 frames per second. With TFM imaging different ultrasonic modes can be defined for longitudinal waves, shear waves and even sound paths with mode conversions, like Long-Long-Trans (LLT), for example. The LLT-technique has the potential to replace traditional tandem techniques due to its advantage concerning space requirements, as only one array probe is needed. Practical results will be demonstrated and discussed within the presentation.

Seit dem Jahr 2012 ist bei der BGH Edelstahl Siegen GmbH ein Prüfportal für Stabdurchmesser von 300 mm bis 1000 mm im Einsatz. Für die Ultraschallprüfung von Stäben mit Durchmessern zwischen 100 mm und 400 mm wurde in der Jahresmitte 2016 ein weiteres Prüfportal in Betrieb genommen. Diese neue Prüfanlage steht im Fokus dieses Beitrags. ;Da die zu prüfenden Stäbe bis zu 18 m lang sind und das Transportkonzept nur eine seitliche Zuführung der Stäbe erlaubt, musste eine freitragende Prüfbrücke realisiert werden. Am linken Ende der Prüfbrücke wurde eine Kalibrierstation zur schnellen Überprüfung der Prüfempfindlichkeit aller Prüfköpfe installiert. Dadurch beträgt die Gesamtlänge der Prüfmaschine etwas mehr als 32 m, wovon 20,5 m freitragend sind. Zur Sicherstellung einer vollständigen Prüfung mit der erforderlichen Überlappung der Prüfspuren und der nötigen Prüfgeschwindigkeit sind sechs Prüfwagen im Einsatz. Jeder Prüfwagen beinhaltet je ein Prüfsystem für ferritische und austenitische Werkstoffe mit unterschiedlichen Prüffrequenzen. Eine aufwändige Schnellwechsel-Vorrichtung ermöglicht die Umstellung auf den zu prüfenden Werkstoff. Somit sind in der Anlage insgesamt 48 Prüfköpfe verbaut, von denen jeweils 24 Prüfköpfe aktiv sind. Jedes Prüfsystem arbeitet mit 4 Prüfköpfen: Die Prüfung des oberflächennahen Bereiches erfolgt mit einem SE-Prüfkopf auf 0,8 mm KSR. Die Prüfung des Kernbereichs erfolgt mit Senkrecht-Einschallung auf 1,0 mm KSR. Zwei Prüfköpfe sind zur Winkeleinschallung in beide Umfangsrichtungen vorgesehen und werden mit einer 3 mm-Längsbohrung abgeglichen. ;Nach Einlegen der Stäbe werden die Prüfteile in Rotation versetzt und die Prüfsysteme von oben aufgesetzt. Jeder Prüfwagen fährt einen Teilbereich der Stablänge mit schraubenförmigen Prüfspuren zur vollständigen Abdeckung des Prüfvolumens ab. Alle Prüfköpfe arbeiten in Spaltankopplung und sitzen in separaten, kardanisch aufgehängten Prüfkopfhaltern, die eine optimale Nachführung an der Staboberfläche liefern. ;Die Anlage verfügt zudem über eine optische Stabenden-Überwachung mit einem Kamerasystem, eine Return-To-Defect-Funktion, eine komfortable C-Bild-Software mit einer 12-Uhr-Erkennung und eine Farbmarkiereinheit.

Sampling Phased Array, also called Total Focusing Method is known for about 10 years. This technique uses Full Matrix Captured ultrasonic data which is transmitted and received from several incidence points within the same phased array probe. This data yields an ultrasonic image of very high resolution. New portable and rugged Phased Array Flaw Detectors are now available having this signal processing method onboard. After a short description of this rather new technique, we are pleased to present our experiences in practical applications on welded joints. Our goal is to achieve a reproducible sizing of imperfections in the image plus the evaluation of the recorded data by using additional analysis software. This is also possible, even for flat reflectors not lying perpendicular to the typical beam direction. Our practical results gained from welded joints with imperfections (lack of fusion) using conventional Phased Array will be compared to Sampling Phased Array scans, and a possible alternative to standard echo amplitude evaluation will be discussed.

Two ultrasonic testing systems for ERW pipes are put into operation in 2015 at the Polish pipe mill Huta Labedy. They are part of an entirely new production line which is realized by the SMS Group from Mönchengladbach, Germany. The following pipe dimensions were the basis of the project: diameters between 114 mm and 324 mm, wall thicknesses between 3 mm and 16 mm and pipe lengths between 6 m and 18 m. The first ultrasonic inspection is carried out after forming steel strips into a round shape and after producing the longitudinal pipe weld. In this stage, the pipes are “endless”. A test carriage is mounted to a stationary machine stand. The test carriage is placed onto the pipe in the 12 o’clock position and is smoothly guided by means of support rollers. The carriage can be moved into the service position in order to calibrate the testing system with a short test pipe carrying artificial defects. The test pipe is fixed to a motorized calibration unit for a dynamic check of the sensitivity. Five probes are used in this weld testing system: Four angle beam probes for longitudinal defects and one oscillating straight beam probe to check the descarfing process. A final ultrasonic inspection is one of the last steps of the pipe production sequence. A testing bridge is used because of the high throughput requirements of up to 140 pipes per hour. The large testing bridge with a length of approx. 30 m is equipped with testing carriages on both sides. After bringing the pipe weld into the 12 o’clock position, the pipe weld is tested with up to 2 m/s with eight ultrasonic probes using the water jet coupling technique (squirter): Four angle beam probes for longitudinal defects and four straight beam probes for the detection of laminations in the heat-affected zone near the weld. The pipe are then transversely moved beneath the testing bridge and put into rotation. The pipe body is tested in helical tracks with a total track width of 250 mm and a circumferential speed of up to 1.5 m/s. The lamination probes are coupled with the water gap technique. The probe holder mechanics were designed for smooth surface following also for pipe with stronger ovalities and for fast change-over by avoiding the change of mechanical parts/skids.

Ultrasonic Phased Array techniques are applied in medical and technical fields since many years. Due to increasing computer performances now also advanced imaging techniques can be applied, which deliver higher image resolutions compared to traditional sector scans and linear scans which are only based on focused sound beams. The total focusing method (TFM) is a signal processing algorithm using data acquired in full matrix capture mode (FMC). A computation zone is specified for the data reconstruction. This zone is meshed, and for each point on this grid, the focal-laws are calculated for the entire set of elements of the phased-array probe. All recorded signals are time-shifted accordingly before summation at every point of the grid. The loop ends when the reconstruction is done for every point of the mesh. The main advantages of FMC-TFM are direct imaging of a large area in one probe position combined with optimal focusing and spatial resolution. All computations are achieved at a refresh rate up to 30 frames per second. For TFM imaging different ultrasonic modes can be defined for longitudinal waves, shear waves and even sound paths with mode conversions, like for example Long-Long-Trans (LLT). The LLT-technique has the potential to replace traditional Tandem techniques which has the advantage concerning space requirements, as only one array probe is needed. Practical results will be demonstrated and discussed within the presentation.

Several testing procedures for new railway wheels are a mandatory part of the production process. These include an ultrasonic and a magnetic particle inspection. The Schuler Group currently realizes an entire production line for the Turkish company Kardemir. KARL DEUTSCH was appointed to provide the UT and MT system. The production and also the testing line was designed to achieve a high throughput with a total cycle time of approx. 90 s per wheel. The magnetic particle testing system uses a trapezoidal coil, which is pneumatically moved between safety position and test position. The loading of the testing system is carried out by means of a carriage, which linearly moves between the loading position and the testing position. The wheel is oriented in a vertical manner. After moving the wheel into the test position and lowering the magnetization coil, the test is carried out within one full rotation of the wheel. Up to three operators perform the visual inspection under UV light. Therefore, the accessibility of the wheel from three sides and the operational safety for the staff must both be ensured. The ultrasonic inspection is carried out in almost vertical position. The wheel is inserted from above into a water filled-tank where only the wheel flange is immersed. Two phased array probes, each with 128 elements, are mounted in the 6 o’clock position below the wheel. They are used to inspect the wheel flange from two sides (running surface/rim and rim). The wheel hub is tested from both sides with two 64-element phased array probes using the water gap coupling technique. Naturally, the hub probes must be adjustable in height in order to test wheels of varying diameters. Phased array testing allows to quickly inspect the wheels within one rotation. KARL DEUTSCH is shareholder of the French M2M company which provided three modules for the phased array test electronics. A total of 384 parallel test channels is used. Therefore, several shots can be produced simultaneously and the shot sequences can be flexibly arranged. The slightly curved running surface requires a careful adjustment of the delay laws of the phased array probes. Also, the test mechanics must ensure a smooth rotation of the wheel in order to achieve a high test sensitivity.