Describe what "porosity" is in a welding context.

Porosity in welding refers to the presence of tiny gas pockets or voids that become trapped within the weld metal during the solidification process. These gas pockets can be introduced into the weld from several sources, including impurities in the base material, contamination of the welding atmosphere, or the use of improper welding techniques. The presence of porosity within the weld can significantly weaken the integrity of the weld joint, making it susceptible to failure under stress or pressure.

This phenomenon is crucial to understand because maintaining a high-quality weld requires ensuring that no contaminants or gas-forming elements are present during the welding process. Proper welding practices, including controlling the environment and selecting the right materials, can help mitigate the risk of porosity and enhance the strength of the weld joint. This understanding is vital for welders in producing reliable and durable structures.