PSI - Issue 75

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

494 6

a)

a)

Weld Bead

Machined Weld Bead

6

200

100

Fig. 2 a) schematic drawing of the weld bead; b) schematic drawing of machined the weld bead

2.4. X-ray Diffraction Determination of the Subsurface Residual Stress Three different levels of heat input, low (0.52 kJ.mm), medium (1.16 kJ/mm), and high (1.44 kJ/mm), were chosen to evaluate the residual stress in the Duplex Stainless Steel (DSS) 2205 welded specimens. Two samples were tested for each welding condition, with and without the weld bead. The specimens were nominally 150 x 200 x 6 mm . X-ray diffraction residual stress measurements were made at a nominal depth of 59.1x10 -3 in.(1501 x 10 -3 mm). Material was removed electrolytically for subsurface measurement to minimize possible alteration of the subsurface residual stress distribution because of material removal. Measurements were made in the perpendicular to weld direction at three points: in the center of weld (fusion zone), the heat affected zone, and base metal as shown in Figure 3.

Measurements of Residual Stress 1.5 mm

Fig. 3 Schematic drawing of X-Ray diffraction measurement locations in the cross section of the weld at three different positions: 1. Fusion zone; 2. Heat affected zone; 3. Base metal The samples were recked through an angular range of degree around the mean psi angles during measurement to integrate the diffracted intensity over more grains to minimize the influence of the grain size. The value of the elastic constant E/(1 +  ) required to calculate the macroscopic residual stress from the strain measured normal to the (211) planes of the duplex stainless steel 2205 was ½ S2 = 5.92 x 10-6 MPa (24,516 ksi)

[Örnek et. al (2016)] 2.5. Fatigue testing

Duplex Stainless Steel (DSS) will be used as the parent material. For the welding process, a single bead-on-plate (BOP) weld was developed using Robotic g as m etal a rc w elding (GMAW) on DSS plates under different welding conditions. The schematic drawing of the robotic bead-on plate (BOP) weld and the weld bead removed by the machining process for the fatigue specimens are shown in Figures 4a and 4b, respectively. Fatigue specimens were manufactured in accordance with the ASTM E-466-21 (2021) requirements (Figure 5), following the parallel direct direction of the hot-rolled plate. It was evaluated the effect of varying the heat input from a low value of 0.5 kJ/mm to a high value of 1.45 kJ/mm on fatigue life [Pereira do Nascimento et al. (2011)].