Which type of corrosion is commonly found at welds?

Weld decay, or heat-affected zone corrosion, refers specifically to the degradation that occurs in the area surrounding a weld joint. This type of corrosion is particularly prevalent due to the microstructural changes that happen in the heat-affected zone during the welding process. When metals are welded, they are subjected to high temperatures, which can alter their physical and chemical properties. This altered area may be more susceptible to corrosion mechanisms, especially if it includes phases that are less resistant to corrosive environments.

The heat-affected zone may also have uneven structures or reduced corrosion resistance compared to the base metal, leading to localized deterioration. Thus, weld decay is often identified as a critical issue in welded structures, particularly in applications involving corrosive environments, making it important to be aware of during inspections and materials selection.

Understanding this type of corrosion helps in implementing proper welding techniques and material selections to mitigate potential degradation and ensure the integrity of welded joints over time.