Black Stain

Technical Support

Struggling with a specific casting defect or just need general technical support?

  • Very superficial black spots on a good and smooth casting

  • Indicates that the metal reacted with oxygen forming Chromium (Cr) and Manganese (Mn) oxides during melting, casting and solidification

Causes of this defect are evident in the metal and other portions of the process; to cure, R&R recommends taking the following actions:

Metal

High metal and mold temperatures.


Melt under Argon (Ar) blanket and adjust temperatures.





Other

Turbulent casting.


Use a ceramic filter or carbon stucco.




Slow cooling down curve.


Separate molds after casting. Can molds after casting.





R&R is a Proud Member of
ICI Digital Logo.jpg
EICF-logo.gif
MJSA-logo.jpg

Corporate Office

3535 Briarfield Boulevard
PO Box 1570 
Maumee, Ohio 43537 USA
US Toll Free: 800.253.4502
US Phone: 419.865.9497
US Fax: 419.865.9997

Email:

RR-Marketing@dentsply.com

RRCustomerService@dentsply.com

RR-Technical@dentsply.com

Contact Us

R&R Terms & Conditions

© 2019 by Ransom & Randolph