PSI - Issue 75

Carolina Payares-Asprino et al. / Procedia Structural Integrity 75 (2025) 489–500 C. Payares-Asprino et al./ Structural Integrity Procedia (2025)

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a)

b)

Fig. 7a Fatigue specimen with weld bead; Fig. 7b Fatigue specimen weld bead removed

Fig. 7a Fatigue specimen with weld bead; Fig. 7b Fatigue specimen weld bead removed

3. Results and Discussion 3.1. Residual Stress

Three different levels of heat input, low (0.53 kJ.mm), medium (1.16 kJ/mm), and high (1.44 kJ/mm), were chosen to evaluate the residual stress in the 2205 welded specimens with and without the weld bead. The specimens were nominally 150 x 200 x 6 mm. Figure 9 shows the locations and directions perpendicular to the weld for the residual stress measurements for the welds DSS and machined specimens.

b)

a)

Fig. 8 The location and direction perpendicular to the weld for the residual stress measurements: 1: FZ, 2: HAZ, 3BM; fig. 9a) weld bead; fig. 9b) machined the weld bead. Figure 9 shows residual stress behaviour along the perpendicular to weld direction using a heat of 1.44 kJ/mm at the average depth from the surface of 1.438 mm and 1.510 from the weld bead and machine weld samples, respectively. Measurements were made at three points: in the weld, heat-affected zone, and base metal. When analysing this figure, it can be observed that, in general, the presence of tensile residual stresses in the weld bead was slightly higher in the centre of the weld, giving a maximum of 230 MPa than the transition zone with a value of 251 MPa. In the BM, it drops to a compressive stress of -4 MPa. However, it was noticed that the machine welds in the weld area and the HAZ dropped the residual tensile stress to 175 MPa and 115 MPa, a decrease in the residual stress of 27% and 64%, respectively, from the weld bead specimen. Figure 10 shows residual stress behavior in the HAZ along the perpendicular to weld direction for heat input of 0.51 kJ-mm, 1.16 kJ-mm, and 1.44 kJ/mm at the average in depth from the surface of 1.438 mm and 1.510 from the weld bead and machine weld samples, respectively. It is noticed that the residual stress increases when the heat input increases, with the higher residual stress for weld bead specimens welded at 1.44 kJ/mm. The changes in residual stress are probably due to the welding deformation, which occurs during the more extensive thermal excursion. on. When machining weld beads at a constant chip’s cross-sectional area of 0.15 mm 2 , the residual stresses for heat