What are the defects in casting?

If the "defect" in your question is interpreted as "defect"

The mechanical properties of 1. castings are poor. Compared with the products produced by forging, rolling and extrusion, the products produced by casting have loose and dense structures and are prone to cracks.

2. The casting structure is uneven. The structure of castings usually consists of fine grain areas on the outer surface; A columnar crystal region in the middle; Internal equiaxed crystal region.

3. The residual stress is large.

If the "defect" in your question is interpreted as "organizational defect"

Defects such as shrinkage cavity, porosity, shrinkage cavity, inclusion, shrinkage porosity and segregation often exist in ingot or ingot.