An ESI is defined as what?

The correct definition of ESI is "elongated slag inclusion." This term pertains to welding and materials science, referring specifically to a type of defect that can occur in welded joints. Slag inclusions are non-metallic materials that become trapped within the weld metal during the solidification process. When these inclusions are elongated, they can compromise the mechanical properties of the weld, potentially leading to weakened joints or reduced integrity of the pipeline.

Understanding this defect is key for welders and inspectors, as it emphasizes the importance of proper welding techniques and quality control measures to ensure that the welds meet the industry standards. Recognizing and addressing elongated slag inclusions helps in maintaining the robustness and reliability of welded pipelines in various applications.