What does aligned porosity refer to?

Aligned porosity specifically refers to a localized array of porosity that is oriented in a line. This means that the tiny voids or cavities formed during the welding process are not randomly distributed but rather positioned in a linear formation. This can occur due to various factors, such as specific techniques or issues during welding, which might create conditions where gas trapped in the molten weld metal finds a path that causes it to cool and solidify in a linear orientation.

Understanding this concept is crucial in welding inspection, as aligned porosity can be indicative of specific issues related to the welding procedure, such as improper gas shielding or contamination. By identifying and addressing the cause of aligned porosity, weld quality can be improved, and the integrity of the weld can be ensured.