Red Seal Welder Practice Exam

What is a common welding defect characterized by gas pockets trapped in the weld?

1. Cracking

2. Porosity

3. Undercutting

4. Inconsistency

The correct answer is: Porosity

Porosity is a common welding defect that occurs when gas pockets are trapped within the weld metal as it solidifies. This happens when the molten weld pool becomes contaminated with gases, which then lead to the formation of tiny voids or bubbles as the weld cools. These gas pockets weaken the integrity of the weld and can considerably reduce the mechanical properties of the welded joint, making it more susceptible to failure under stress. Understanding porosity is essential for welders because it can be caused by various factors, including the presence of moisture, improper shielding gas coverage, or contaminants on the base material. Identifying and addressing porosity is crucial for ensuring the quality and durability of welded structures. The other options point to different types of defects or issues that do not involve the gas pockets as characterized by porosity. For example, cracking refers to fissures that may develop in the weld metal or heat-affected zone, often due to tensile stresses, rapid cooling, or unsuitable joint design. Undercutting is an issue where the base metal is melted away at the toe of the weld, creating a groove that can reduce the strength of the joint. Inconsistency may refer to variability in the welding process or results but does not define a specific defect related to