The undercut groove is where melted base material has been drawn into the weld and not allowed to wet back properly because of the rapid solidification. Melted portions of the base plate are affected in the same way. The forces of surface tension have drawn the molten metal along the edges of the weld bead and piled it up along the center. When the travel speed is too high, the weld bead will be very peaked because of its extremely fast solidification. This type of defect is most commonly caused by improper welding parameters particularly the travel speed and arc voltage. It is most common in lap fillet welds, but can also be encountered in fillet and butt joints.
Welding distortion is caused by the non-uniform expansion and.ĥ UNDERCUTTING As shown in Figure 10-3, undercutting is a defect that appears as a groove in the parent metal directly along the edges of the weld. What are the possible welding defects and how the same can. The defects in the weld can be defined as irregularities in the weld metal produced due to incorrect welding parameters or wrong welding.
