[en] Non-destructive testing methods have been greatly improved in the last 10-15 years, thanks to progress related to probes, equipment, and simulation. By the Phased Array Ultrasonic Testing (PAUT) method it is possible to master the ultrasonic inspection beam, to reach the desired properties (incidence angle, beam width) with respect to the targeted flaws within a given, arbitrary component. With this opportunity it has been possible to customize test parameters and to adapt to various materials and shapes. This possibility allows to determine the location and orientation of material discontinuities, due to the material properties. With this we can increase the probability of detection of anomalies through reduced uncertainties of the inspection thanks to the phased array versatility. There are so many dissimilar metal welds (DMW), what are only can be reached very difficultly from the austenitic side because of the geometry of the welds although the defect mainly can be found on the fusion line or in the heat affected zone (HAZ). However, because of the coarse-grained microstructure and unknown orientation of grains, attenuation is higher in austenitic welds than carbon steels, and it baffles the testing. In case of dissimilar metal welds, which have been already performed, based on known grain size and orientation, or in case of designed welds, based on software identified properties, optimal ultrasonic beam can be chosen. The material properties have been already extensively studied in EURATOM Framework projects within NUGENIA partnership such as BIMET and ADIMEW, STYLE and MUTIEMATAL form structural integrity point of view. Those projects helped us to understand the behaviour of the DMWs and supported us necessary information about the grain sizes and orientations of the weld and buttering layer. Based on that numerical simulation allows to observe the effects of circumstances of tests helping to choose the optimal test parameters. (author)