Time-of-flight diffraction ultrasonics

About: Time-of-flight diffraction ultrasonics is a research topic. Over the lifetime, 544 publications have been published within this topic receiving 3189 citations.

Detection and Sizing of Defects in Complex Geometry Weld by Manual Ultrasonic Time of Flight Diffraction Inspection

Abstract: The basic aim of this current research is to reliably detect and size defects in complex geometry welds using the well-known ultrasonic time of flight diffraction (TOFD) technique. A complex geometry weld specimen with various artificial defects was designed and fabricated. Different combinations of probe angles and probe center spacings were used in experiments for determining the optimum one. TOFD models were also developed for sizing the defects and experimentally verified.

Spiral welding seam manual scanner

Abstract: The utility model is a spiral weld manual inspection device walking on a pipe when used for phased array binding TOFD ultrasonic test serviced steel pipe spiral welding. The utility model, which essentially comprises an inspection frame (1), a probe frame (6), a rolling wheel mechanism and an encoder mechanism, relates to tests of equipments which are not included in other kinds and the pipe system technical field. Four corners of the rectangular inspection frame (1) are equipped with the rolling wheel mechanism. The probe frame (6) is arranged on a probe frame moving rail (4) on two sides of the inspection frame (1). The encoder mechanism is arranged on one external side of the inspection frame (1). The inspection device walks stably and reliably when testing the serviced steel pipe spiral welding. The position of the probe can be always precisely parallel to the pipe welding surface and keep a certain distance away from the pipe welding surface. The manual inspection device with reliable and accurate test is provided for the phased array binding TOFD ultrasonic test serviced steel pipe spiral welding.

Time of Flight Diffraction Testing of Austenitic Stainless Steel Weldments at Elevated Temperatures

Abstract: Ultrasonic testing is a mandatory requirement during inservice inspection of the welds in the main and safety vessels of a prototype fast breeder reactor. Presently, conventional ultrasonic techniques have been proposed for use. Two of the main challenges likely to be encountered during ultrasonic testing are the high temperature of the vessels (around 423-473 K during shutdown) and the background radiation. Ultrasonic time of flight diffraction is now well established as a technique for NDT of thick (greater than 12.5 mm) weldments. The main advantage of using time of flight diffraction is its increased accuracy for discontinuity detection and fast scanning times. Conventionally, time of flight diffraction has been applied only for carbon steel weldments and at ambient temperatures. This paper highlights the successful application of time of flight diffraction for testing of stainless steel weldments at high temperature (423 K). Experimental studies reveal that the diffracted signal amplitude decreases and, hence, the time of flight diffraction image contrast decreases with increasing temperature. Additional gain was necessary to compensate for the decreased signal amplitude. Analysis of the experimental data indicated that the additional gain necessary to compensate for the lower signal amplitude varied nonlinearly (quadratically) with temperature. The errors in the discontinuity dimensional measurement were observed to be less than 5% compared to measurements at ambient temperature.