Carbon Buildup Defect
Defects
Cause
Carbon buildup is a defect that can occur in castings when deposits from lubricant, or water mixed with lubricant, accumulate on the die surfaces.
Corrections
- Check lubricant application:
- Use the minimum amount of lubricant.
- Increase the die temperature, reduce the cycle time, adjust the water flow, or adjust the spray pattern to reduce lubricant buildup.
- Even out the die temperature to eliminate hot and cold spots.
- Do not arbitrarily change the lubricant mixture or amount applied, especially from shift to shift.
- Use the correct lubricant for the die temperature, especially when using a cold die. (Measure the die temperature and verify with the lubricant supplier that the lubricant will work at that temperature.)
- Avoid spraying lubricant into blind fins, cores, and other cold areas.
- Carefully remove excess lubricant with an air blow-off.
- Do not use hard water to mix with lubricant.
Please note that the information provided in this article is intended to be a general guide to the causes and corrections of carbon buildup defects in metal castings. However, it is important to note that the specific cause and correction of any particular defect will vary depending on the specific casting process, alloy, and other factors. Therefore, it is important to consult with an experienced and professional engineer to ensure that the correct diagnosis is made and the most suitable correction is chosen.