PSI - Issue 37

Aleksandar Sedmak et al. / Procedia Structural Integrity 37 (2022) 263–268 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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Welded turbine cover (Fig. 2a) is leaned on upper ring of guided vane apparatus Fig. 1, undergoing the axial force Pu=16.9 MN in regular regime, also supporting moving parts of generator (8 MN), as well as few other turbine components (5 MN). Thus, the total static loading in axial direction 29.9 MN, whereas in irregular regime it is 35-45 MN. Dynamic component of axial force (P D ) is circa 5% of Pu, whereas amplitude fatigue loading is equal to the axial force Pu, with annual frequency 2000. 2. Experimental investigation 2.1. Results of NDT testing In the scope of this investigation, the base metal and welded joints have been tested by two non-destructive techniques (NDT), magnetic particles (MT) and ultrasound (UT). Results of testing are shown in Fig. 3 (MT) and Fig. 4 (UT).

Figure 3. Locations of surface defects detected by MT

Figure 4. Locations of surface defects detected by UT