Poor slag control during welding most commonly results in which defect?

Poor slag control during welding most commonly results in which defect?

• A. Slag inclusions
• B. Porosity
• C. Cracking
• D. Lack of fusion

Answer: (A)

Slag is the nonmetallic by-product that forms on top of the weld pool when using flux-based processes. If slag control is poor, slag can be left on or dragged into the weld as the metal solidifies, becoming embedded as nonmetallic pockets. These pockets are slag inclusions, which are a common defect when the slag isn’t properly cleared or remelted with subsequent passes. Porosity, cracking, and lack of fusion have different main causes—gas entrapment or moisture for porosity, hydrogen-related or thermal stresses for cracking, and insufficient heat or improper technique for lack of fusion—so they’re not the direct consequence of poor slag control as frequently as slag inclusions.

Slag is the nonmetallic by-product that forms on top of the weld pool when using flux-based processes. If slag control is poor, slag can be left on or dragged into the weld as the metal solidifies, becoming embedded as nonmetallic pockets. These pockets are slag inclusions, which are a common defect when the slag isn’t properly cleared or remelted with subsequent passes. Porosity, cracking, and lack of fusion have different main causes—gas entrapment or moisture for porosity, hydrogen-related or thermal stresses for cracking, and insufficient heat or improper technique for lack of fusion—so they’re not the direct consequence of poor slag control as frequently as slag inclusions.