THE ROLE AND SIGNIFICANCE OF NON-DESTRUCTIVE TESTING FOR THE SAFETY AND RELIABILITY OF STRUCTURES WITH THICKENED WELDS MADE FROM STRUCTURAL

U radu je teoretski i praktično obrađena primjena kontrole bez razaranja (KBR) na zavarene konstrukcije. Obrađene su metode KBR-a s naglaskom na zavarene spojeve i prikazan je pristup kako pratiti pouzdanost ovih procesa. Također je prikazana i važnost KBR-a za sigurnost konstrukcije s obzirom na opasnosti koje nastaju uslijed koncentracije naprezanja. Posebno je naglašena kontrola ultrazvukom zbog njene važnosti kod ocjene homogenosti zavarenog spoja po presjeku zavara. Dan je kratki opis konstrukcijskih čelika s naglaskom na sitnozrnati čelik S355J2 + N koji je u širokoj primjeni pri izradi zavarenih konstrukcija za hidroturbine i generatore. Na primjeru zavarene konstrukcije izlazne cijevi (difuzora) hidroturbine, izvršena je kontrola bez razaranja sa više metoda KBR-a čime je praktički u pogonskim uvjetima pokazan značaj i uloga KBR-a.In this graduate thesis the application of non-destructive testing (NDT) on welded constructions is theoretically and practically processed. The NDT methods with emphasis on welded joints have been elaborated and the approach is shown to monitor the reliability of these processes. It also shows the importance of NDT for construction safety with regard to hazards arising from stress concentration. Ultrasound control is particularly emphasized because of its importance in assessing the homogeneity of the welded joints on its cross section. A brief description of structural steels with an emphasis on fine-grained S355J2 + N steels which is widely used in the construction of welded structures for hydro turbines and generators. On example of draft tube a non-destructive inspection of several NDT methods was performed, demonstrating the importance and role of NDT in practical operating conditions