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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Nine single bead-on-plate were developed using the welding conditions selected in Table 2. Bead-on-plate welding was conducted in this research to avoid distortion, obtain suitable geometry, get rid of clamping, and eliminate the adjustments of gap and mismatch of welds. The weld plates were cut into two pieces with the exact dimensions to measure the residual stress with and without the weld bead. Figure 2a shows the schematic drawing of BOP welds with their final dimension. The term “Heat Input” (HI) is defined as “Arc Energy. The recommended arc energy depends primarily on the type of material being used; for the 22%Cr grades, a heat energy between 0.5- 2.5 kJ/ mm has been recommended for plates with thickness between 6 -15 mm [AVESTA (2020)]. Equation 1 is used for heat input (HI) calculations. [AVESTA (2020)].

(1)

Where HI ( / ); I: Arc Current (A); E: Arc Voltage (V), WS: (mm/min) Table 4. Welding conditions Sample HI[kJ/mm] Voltage (V)

Arc Current (A)

WS (mm/min)

1 2 3 4 5 6 7 8 9

1.28 1.16 0.62 1.39 1.04 0.53 1.44 1.22 0.57

26.5 26.5 26.5 25.0 25.0 25.0 28.0 28.0 28.0

235 250 270 270 235 250 250 270 235

290 370 700 290 370 700 290 370 700

2.3. Machining Parameter for weld specimens The cutting parameters selected for this study were the cutting speed (Vc), the feed per tooth (fz), the depth of cut (ap), and chips cross-sectional area as a machining variable ( = ∙ ), since from limited previous research it was observed that these variables had most influence on the residual stress. Selected cutting parameters were recommended from the manufacturer for the parent metal and are shown in Table 5. We finished the SolidWorks® model needed to machine the weld bead of the weld specimens to measure the residual stress. A HAS CNC milling equipment will be used for the face milling operation of the welds. Figure 2b shows the schematic drawing of the machined weld bead. At a different set of machining parameters, researchers found that independently of heat input, non-tensile stresses were developed when machining at a constant chip cross-sectional area of 0.2 mm 2 (small amount of material removal), [Payares-Asprino et. al. (2019)]. Based on those results, a lower machining parameter of chip cross-sectional area av = 0.15 mm 2 was set up to evaluate the effect on residual stress and fatigue behavior in duplex stainless-steel welds.

Table 5. Selected Cutting Parameters Machining Parameters Vc (m/min)

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fz (mm/rev*tooth)

0.123

ap (mm) av (mm 2 )

0.31 0.15