PSI - Issue 11
Hizadora Constanza Medina D’Ambros et al. / Procedia Structural Integrity 11 (2018) 114–121 Author name / Structural Integrity Procedia 00 (2018) 000 – 000
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Table 1. Defects identified after the weld at samples E-REF, E-HIGH, E-LOW, E-SLAG and E-MOIST. Defects E-REF E- HIGH E- LOW E-SLAG E-MOIST Excess weld metal x x x x Overlap x x x x Uneven weld bead ripples x x x x Weld spatter x x x Porosity x x x Longitudinal cracking x x x Slag inclusions x x x Undercut x x Lack of fusion x x Excessive penetration x Incomplete root fusion or penetration x
The most common defects were excess weld metal, overlap, uneven weld bead ripples (four from five groups of samples). In all this case the preventive measure are related to welding amperage and the electrode manipulation and also electrode travel and work angle, which correspond to the samples E-LOW, E-SLAG and E-MOIST. Porosity is related to the environment conditions such as the use of moisture and wind, then it is expected to be found in E MOIST samples. Longitudinal cracking and slag inclusions are influenced by the base metal conditions and the incorrect amperage with correctly correspond to E-HIGH, E-SLAG samples (Kobe Steel, 2015). The Fig. 7 shows the aspect of the defects mentioned at weld joint samples.
Fig. 7. Defects identified after the weld at samples: (a) porosity, slag inclusions, lack of fusion, overlap; (b) undercut, weld spatter, porosity, lack of fusion; (c) uneven weld bead ripples, slag inclusions, longitudinal cracking.
In other hand, the less common defects were excessive penetration and incomplete root fusion or penetration (one from five groups of samples each one). The excessive penetration occurs just in E-HIGH, one cause of this defect is the high heat input to the joint which corresponding to the joint pathology. Also the incomplete root fusion or penetration was identified at E-SLAG sample because of the slag itself, which trapped in the weld, when the next layer is deposited, the entrapped slag is not melted out (TWI, 2018). The Fig. 8 show results of tensile strength test of E-REF, E-HIGH, E-LOW, E-SLAG and E-MOIST samples.
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