Magnesium content in the casting which is preserved as a residue after treatment and the associated bonding of the sulfur. Determination of an optimum magnesium residual content for the existing product mix is a very important task that also serves for quality assurance. The following factors have to be taken into account in this context:
- Time between the treatment and the last casting process
- Number of recasting operations
- The lowest magnesium content required for the last casting
- Fading characteristic of the magnesium in the melt which has to be determined specifically for each foundry
- Sulfur content of the melt after treatment
The residual magnesium content should generally be between 0.035 and 0.055%.
Nodular graphite cast iron