Regarding weld defects, what is the characteristic of a “porosity” defect?

Porosity is specifically characterized by the formation of small gas pockets or voids within the weld metal that occur during the solidification phase. When the molten weld metal cools and solidifies, gases that are present in the weld area may not have a way to escape, leading to these trapped gas bubbles. This defect can result from various factors, such as contamination of the base material or welding consumables, presence of moisture, or improper shielding gas coverage.

Understanding this characteristic emphasizes the importance of maintaining clean working conditions and ensuring adequate shielding during the welding process to produce a defect-free weld. Other choices, while they may relate to welding conditions, do not accurately define what porosity is, as they deal with different aspects of weld quality and performance.