Visual Testing (VT) Practice Exam

A discontinuity resembling a trail left in striking a match, appearing beside a weld, is known as what?

1. Linear porosity.

2. Arc strikes.

3. Undercut.

4. Slag.

The correct answer is: Arc strikes.

The phenomenon described—a discontinuity resembling a trail left in striking a match, which appears beside a weld—is recognized as arc strikes. Arc strikes occur during the welding process when the welding electrode or the arc itself unintentionally makes contact with the base metal, creating a small molten pool that cools into a hardened mark beside the weld bead. This can happen if the welder is not careful with the electrode's positioning or if there are interruptions in the welding process. Arc strikes can be detrimental because they can lead to cracking or other structural weaknesses in the welded components. Proper welding techniques and training help minimize the risk of arc strikes, which is crucial for ensuring the integrity of the weld. Understanding the significance of arc strikes is essential for any welding professional, as they must learn to distinguish between acceptable and unwanted marks on the weldment for quality control in their work. The other terms refer to different types of welding defects or anomalies and do not describe the specific nature of the discontinuity that resembles a trail. Therefore, identifying this particular issue as an arc strike is accurate and supports the importance of precision and care in the welding process.