enrichment layer
1.In ambient temperature, the enrichment is caused mainly by the diffusion of substrate elements passing through the defect and grain bo-undary of the coating layer and then spreading over the surface by surface diff-usion.
2.After completion of a dam, the natural environmental change at the dam site helps the enrichment of organic materials in the reservoir, resulting in the generation of erosive CO 2 in the lower layer of the water. In the transferring process of the erosive water toward the dam foundation, physiochemical reaction occurs between the water and the rock of the dam foundation.
