Why is porosity a significant defect in welds?

Porosity is a significant defect in welds because it introduces gas-filled voids within the weld metal, which compromises the weld's overall strength and structural integrity. These gas pockets can weaken the weld, making it more susceptible to cracking, fatigue, and failure under load. For welded structures and components, strength and durability are critical for safe and effective performance; therefore, any defect that undermines these qualities, such as porosity, is a serious concern.

This defect can arise from various factors, including contamination during the welding process, improper shielding gas coverage, and moisture in the materials being welded. Ensuring high-quality welds requires controlling these factors to minimize or eliminate porosity, as even small amounts of porosity can have a detrimental impact on weld performance, especially in high-stress or high-temperature applications.