Atlas of Casting Defects
Negative
A multiplicity of dark colored shallow depressions covering a large portion of the casting
N/A
Thick, slow to cool sections
Chrome Oxide Pitting, Fusion Spot, Measles
Alloy, number of defect sites, depth of defect
Oxygen reacts with chrome in the metal immediately after casting
| Area | Possible Cause | Potential Correction |
|---|---|---|
| Foundry | Surface oxidation of high chrome-iron alloys |
Ensure reducing or inert conditions immediately after casting. Cover the molds after casting. Use carbonaceous materials in or around the mold. Cool in vacuum or protective or inert atmosphere |
| Foundry | Lack of carbonaceous material in mold |
Reduce mold burnout time or add additional carbon layers during shell building |
| Foundry | Casting cooling rate too slow |
Increase casting cooling rate |