What is a potential result of a lack of penetration during welding, classified under processing discontinuities?

The potential result of a lack of penetration during welding, classified as a processing discontinuity, is incomplete fusion. This occurs when the weld metal does not properly merge with the base material, leading to weak points in the weld. Adequate penetration is crucial for ensuring the strength and integrity of a weld, as it allows the filler material to reach a proper depth and bond with the base metals effectively.

Incomplete fusion can result from various factors, including insufficient heat during the welding process, improper technique, or incorrect settings on welding equipment. This type of discontinuity may compromise the performance of the welded joint, possibly leading to failure under stress or load.

In contrast, while other options such as surface cracks and internal voids can result from various issues within the welding process, they are not directly associated with a lack of penetration. Surface cracks typically arise from rapid cooling or stress, while internal voids are often caused by trapped gases or impurities. Uneven thickness is primarily a result of fabrication or design issues rather than a direct consequence of penetration issues in welding.