Which of the following is a possible cause of slag inclusions?

Slag inclusions are commonly caused by improper welding techniques, which can affect the cleanliness and quality of the weld. When the welder does not execute the technique correctly, it can lead to the entrapment of slag within the weld bead. This can happen due to insufficient cleaning of the weld area before starting, improper manipulation of the welding arc, or not allowing the slag to be removed adequately before adding subsequent layers of weld. By ensuring proper technique, welders can minimize the risk of slag becoming trapped in the weld, thus achieving a cleaner and more resilient joint.

While excessive current, incorrect joint fit-up, and improper cooling can also affect weld quality, they generally lead to different types of defects rather than specifically creating slag inclusions. Excessive current could lead to other issues such as burn-through or excessive spatter, but it does not directly correlate with the trapping of slag. Incorrect joint fit-up may result in poor penetration and inconsistent weld profiles, but again, not particularly promoting slag inclusion. Improper cooling can lead to problems such as cracking or warping but does not primarily cause slag inclusions. Hence, the focus on bad welding technique stands out as the primary factor in causing this specific defect.