I am facing a problem of presence of dark residue on shot peened surface. I dont have deep knowledge of this process so I apologize if the question is very basic.
Practiaclly we are shot peening some parts made of Fe ARMCO or Nickle, but post shot peening if we rub a cotton bud on the surface it becomes dark. We are using glass beads type AGB10. My assumption is that this is because the glass beads are getting broken and leaving their residue. I tried to change the air pressure but nothing changed. Is it normal? The parts that we are shot peening have to be in an X ray tube so surface cleaning is very critical to us.