Which type of weld discontinuity is typically acceptable in many welding processes?

In the context of the Structural Welding Code – Steel (D1.1), minor slag inclusion is generally considered an acceptable type of weld discontinuity provided that it does not detract from the mechanical properties or structural integrity of the welded joint. Slag inclusions occur when non-metallic elements from the weld pool become trapped in the weld metal. The code recognizes that small amounts of slag inclusion may not significantly compromise the weld, especially if they are evenly distributed and limited in size.

The acceptance of minor slag inclusion is based on its limited potential to cause issues in most structural applications. Inspectors will take into account factors such as location, size, and overall quality of the weld when determining the acceptability of these discontinuities. In contrast, other types of discontinuities like cracks, pores, and severe undercut are typically unacceptable because they can lead to significant structural weaknesses and failures in welded connections.