Which defect is characterized by gas pockets trapped in the weld metal?

Which defect is characterized by gas pockets trapped in the weld metal?

• A. Slag inclusion.
• B. Porosity.
• C. Cracks.
• D. Undercut.

Answer: (B)

Gas pockets trapped in the weld metal are porosity. This happens when the protective shielding gas doesn’t completely cover the weld pool or when there are contaminants like oil, moisture, rust, or dirt on the metal, or when welding parameters cause excessive turbulence or rapid cooling. As the weld solidifies, the entrapped gas forms tiny voids that show up as holes in the weld and can weaken it. Other defects are not gas pockets: slag inclusion is nonmetallic material trapped in the weld, cracks are actual fractures, and undercut is a groove at the weld toe from insufficient filler or too high travel speed.

Gas pockets trapped in the weld metal are porosity. This happens when the protective shielding gas doesn’t completely cover the weld pool or when there are contaminants like oil, moisture, rust, or dirt on the metal, or when welding parameters cause excessive turbulence or rapid cooling. As the weld solidifies, the entrapped gas forms tiny voids that show up as holes in the weld and can weaken it.

Other defects are not gas pockets: slag inclusion is nonmetallic material trapped in the weld, cracks are actual fractures, and undercut is a groove at the weld toe from insufficient filler or too high travel speed.