Assuring the quality and correctness of the welds is of great importance to nuclear industry. Strict safety requirements are leading to increased demands for the inspection and maintenance of such components. Nowadays, the most common NDT inspection methods for welds are conventional ultrasonic inspection and X-ray inspection. However, these inspection methods have several disadvantages that promote the research of other inspection techniques. This study analyses the ultrasonic behaviour of the beams depending on the grain orientation located in the weld. The grain orientation has been defined using different models (Langenberg, Schmitz, Ogilvy). Apart from the ultrasonic beams generated by conventional ultrasonic transducers, beams generated by linear and matrix phased-array transducers have been analysed. CIVA software, a specific ultrasonic tool, has been used for that purpose, and the results obtained have been validated in the laboratory.