Home / R&R Academy / Defect Analysis / Other Defects / Black Stain

Black Stain

black-stain.jpg

Black stain presents as very superficial black spots on a good and smooth casting. This defect indicates that the metal reacted with oxygen forming Chromium (Cr) and Manganese (Mn) oxides during melting, casting and solidification. 

Technical Support

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

Email our technical team at: Technical@ransom-randolph.com.​

The causes of this defect are evident in the metal and other portions of the process. To cure these causes, R&R recommends taking the following actions.