Phased array ultrasonic testing methods for welds in bogie frames of railway vehicles

Optimal inspection schemes that use phased array ultrasonic testing (UT) methods have been developed for inspecting welds in the bogie frames of railway vehicles. Applying conventional UT methods has two problems: one is the need to take measurements using two processes in order to detect all of the weld defects; the other is the long measurement time needed in cases where there is an obstacle such as a roll inside the side-beams, like a pipe. To overcome these two problems, an array probe can be placed on the outside surface of a side-beam to measure welds by the direct and double traverse techniques. The calculation for sectorial scanning when using the phased array UT methods theoretically indicated that it can cover the entire weld area of a bogie frame. Experiments were conducted using simulated weld test-pieces to confirm that the developed UT methods could detect 1 mm-diameter side-drilled holes at a high level of sensitivity Then, inspection demonstration experiments bra trial product were conducted to confirm that these developed UT methods allow defects of the certain types and sizes that occur during the welding process to be detected and to show that the detection performance was equal to or greater than that of conventional UT methods. The developed UT methods were proven to be effective and are potentially of use for inspecting welds on a bogie frame. These methods are expected to contribute to testing with a higher level of dependability