Yijie EJER has released a technical analysis on the mechanism of Hall flow rate decline in 316L stainless steel powder after long-term storage and the associated regeneration process. The report notes that after storage, even when the particle size report shows little change, phenomena such as reduced Hall flow rate, poor funnel discharge, and local thickness unevenness in the powder spreading layer can still occur. The core causes involve the combined effects of surface-adsorbed water films, capillary liquid bridges, slight oxidation, and fine powder agglomeration. At the mechanistic level, 316L powder has a relatively large specific surface area. As humidity rises, the surface water film develops from a monolayer to multiple layers, capillary condensation occurs at particle contact points and generates additional adhesion forces, forming arches in the Hall funnel that lead to flow interruption. Surface hydroxylation and slight oxidation enhance inter-particle friction and hydrogen bonding, and fine particles form weak agglomerates under van der Waals forces and liquid bridge forces. Vibration during transport may also cause particle size segregation. The regeneration process uses low-temperature vacuum drying to desorb physically adsorbed water, matched-mesh sieving to break up weak agglomerates, and completes cooling, transfer, and storage in a low-humidity environment. After sieving, the particle size distribution, apparent density, and Hall flow rate are re-tested. The analysis explicitly links powder flowability to the powder spreading step in metal additive manufacturing: after vacuum drying and sieving regeneration, the surface water film on the powder is reduced, weak agglomerates are broken up, the Hall flow rate and apparent density are more stable, and thickness fluctuations in the powder spreading layer are reduced, which helps lower the risk of defects such as layer lines, local lack of fusion, and porosity. Regenerated powder must be blended with new powder at a validated ratio, and powders subjected to multiple cycles should be tracked for changes in oxygen content and morphology.