Define porosity in a weld and a common cause.

Define porosity in a weld and a common cause.

• A. Porosity is cracks in the weld caused by shrinkage
• B. Porosity is gas pockets trapped in the weld metal; caused by moisture, oil, dirt, or improper shielding
• C. Porosity is an electrical fault of the arc
• D. Porosity is a decorative weld pattern

Answer: (B)

Porosity refers to gas pockets trapped in the weld metal as it cools and solidifies. A common cause is contamination or inadequate shielding: moisture on surfaces, oil, dirt, or insufficient shielding gas coverage (or contaminated electrodes), which lets atmospheric gases mix with the molten weld and become trapped as voids. This weakens the weld and is not the same as cracks, electrical faults, or a decorative pattern.

Porosity refers to gas pockets trapped in the weld metal as it cools and solidifies. A common cause is contamination or inadequate shielding: moisture on surfaces, oil, dirt, or insufficient shielding gas coverage (or contaminated electrodes), which lets atmospheric gases mix with the molten weld and become trapped as voids. This weakens the weld and is not the same as cracks, electrical faults, or a decorative pattern.