In the context of welding defects, what are inclusions?

Inclusions refer to foreign materials that become trapped within the weld during the welding process. These materials can be various contaminants, such as oxides, slag, or even bits of base metal or filler material that did not fully melt or fuse during welding. The presence of inclusions can weaken the weld joint, adversely affecting the overall strength and integrity of the welded structure. Understanding the nature of inclusions is crucial for weld quality control, as they can lead to potential failures in the welded assembly if not identified and addressed during the welding process.

The other options describe different types of welding defects but do not define inclusions accurately. Surface materials typically involve issues like spatter or oxidation, while cracks refer to specific fractures often caused by thermal or mechanical stresses, and excessive heat regions pertain to areas impacted by overheating during the welding process. Each of these defects presents its own challenges and requires distinct inspection and remediation techniques.