Blowholes/pinholes - Casting defects

Blowholes/pinholes - Casting Defects

Figure 1: Blowholes/Pinholes.

Defect name: Blowholes/pinholes
Record No.: 43
Type of defect (Internal/Surface): Internal, surface
Defect classification: Casting defects
Steel name: Cast iron
Steel composition in weight %: No data.
Note: Your casting has smooth-walled, rounded cavities of various sizes clumped together in one area.
Blowholes/Pinholes—The interior walls of blowholes and pinholes can be shiny, more or less oxidized or, in the case of cast iron, covered with a thin layer of graphite. The defects can appear in any region of a casting. They are caused when gas is trapped in the metal during solidification.
Reference: Not shown in this demonstration version.