6. Defects

This section presents a non-exhaustive list of faults that can occur during MIG/MAG welding.

• Channel

  The channel is a linear defect. It takes the form of a groove located at the foot of the bead (figure 11 ). This defect reduces the effective cross-section and produces a geometric accident generating a high stress intensity factor and reducing the fatigue life of the joint. It is produced by various factors:

  • too high a feed speed ;

  • incorrect torch orientation;

  • arc voltage too high;

  • too high an intensity.