What characterizes "weld porosity"?

Weld porosity is specifically characterized by the presence of small holes or voids within the welded joint, which are typically caused by trapped gases during the welding process. When the molten metal solidifies, gases that are not able to escape can become entrapped, leading to these pore-like defects. This condition can significantly weaken the integrity of the weld and reduce its overall strength, affecting the performance of the welded structure.

The other options do not accurately reflect the definition of weld porosity. Irregularities in the bead pattern may describe different surface defects but do not specifically define porosity. A smooth surface finish refers to an aesthetic quality of the weld bead, which contrasts with the idea of holes or voids. Lastly, increased strength of the welded joint is not an aspect of porosity, as porosity typically compromises the strength and durability of the weld rather than enhancing it.