PSI - Issue 33

Wei Song et al. / Procedia Structural Integrity 33 (2021) 795–801 Author name / Structural Integrity Procedia 00 (2019) 000–000

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welding processing. Two or three passes were added during the back-chipping process. One note that the inner-pass temperature is controlled below 80°C. Finally, the welded joints of EM and UM were displayed in Fig. 1(b) (c). Fig. 2 demonstrates the back-chipping formation processing of the EM welded joint. The back-chipping process was then implemented by removing the welded material and filling the zone of removing material by three passes. The joint shape in the FE model is almost consistent with the actual welded joint. During the calculation of residual stress, the forming process of butt-welded joints was established by a two-dimensional (2D) computational model in ABAQUS software. The element type of C3D8R with three translational degrees of freedom at each node was selected in the thermal-mechanical analysis.

(a)

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Centerline

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16mm

(b)

(c)

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8

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Back chipping

Back chipping

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5 mm

10

5 mm

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Evenmatched welded joints

Undermatched welded joints

Fig. 1 Geometry scheme of multipass welded plate and joints

Path 2 nd Path 1 st

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1 2 3

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Fig. 2 Fabricating processing of multipass welded joints including the back-chipping step

2.3. Residual stress measurement The hole-drilling strain-gauge method was employed to calculate welding stress magnitudes near the welded joints' surface after drilling a small hole in the strain-gauge rosette center. Fig. 3 shows that the schematic diagram results of residual stress measurement. The locations of measurement points in the plate are located on the front side, described in Fig. 3(b). To measure the accurate results near the weld beam center location, the local reinforcement is removed by the milling process. The final cutting depth is 1 mm under the top surface. A slow milling speed is utilized to avoid additional residual stress during the process. 2.4. Metallurgical analysis In terms of the metallurgical proportions, 10CrNi3MoV belongs to the ferric steel, which owns a body-centered