Red Seal Welder Practice Exam

What is the most common defect found in welds?

1. Burn-through

2. Porosity

3. Undercut

4. Incorrect bead shape

The correct answer is: Porosity

Porosity is the most common defect found in welds, primarily caused by trapped gas bubbles within the weld metal during the cooling process. These gas bubbles can originate from several sources, such as moisture, impurities in the welding environment, or from the base materials themselves. The presence of porosity compromises the integrity of the weld, as it can lead to reduced strength and overall performance of the welded joint. Understanding and recognizing porosity is essential for welders to implement corrective measures, such as improving shielding gas coverage, ensuring proper electrode handling, and maintaining a clean work area to minimize contamination. While other defects like burn-through, undercut, and incorrect bead shape can occur in welding, they are typically less frequent than porosity. Each defect carries unique implications and requires specific prevention strategies, but the prevalence of porosity makes it a critical focus in quality control and welding education.