A New Model-Based Approach for Ultrasonic Testing of Dissimilar Welds

A new model-based approach for ultrasonic phased-array testing of dissimilar welds based on the direct measurement of the wave speeds inside the real weld by using scanning laser vibrometry is presented. With this technique the interaction of different wave modes with the weld can be studied in detail leading to important consequences for the measuring set-up. Together with the geometry of the weld as extracted from photo micrographs, an appropriate time-of-flight model including ferritic and austenitic regions, welding zone, buttering and cladding is defined and used for the optimization of focal laws. The whole approach was implemented into the new phased array system PCUSpro Array developed at Fraunhofer IZFP in Dresden. A first successful application of the equipment in a test setup of a customer is presented and discussed.