Incomplete fusion is sometimes described as overlap. Which statement best describes it?

Incomplete fusion is sometimes described as overlap. Which statement best describes it?

• A. It results in complete fusion with the base metal.
• B. Weld metal flows over unwelded base metal without fusing.
• C. It only occurs with gas welding.
• D. It improves weld integrity.

Answer: (B)

Incomplete fusion means the weld metal does not bond to the base metal or to a previous weld bead, leaving unbonded areas even though metal is present. The statement describing weld metal flowing over unwelded base metal without fusing matches this idea exactly: there’s metal over the base, but no bonding at the interface. This is not the same as complete fusion, which means a full metallurgical bond. It can occur with various welding processes, not just gas welding, and it does not improve weld integrity—in fact, it weakens the joint and can lead to failure.

Incomplete fusion means the weld metal does not bond to the base metal or to a previous weld bead, leaving unbonded areas even though metal is present. The statement describing weld metal flowing over unwelded base metal without fusing matches this idea exactly: there’s metal over the base, but no bonding at the interface. This is not the same as complete fusion, which means a full metallurgical bond. It can occur with various welding processes, not just gas welding, and it does not improve weld integrity—in fact, it weakens the joint and can lead to failure.