I’m looking for some help with case hardened sheetmetal parts. We have some failed sheet metal parts – 1mm thick C-1018 steel – that have cracked in the corners, and I suspect a change in the process from a matte black Nitrotec (nitrocarburize) to some other hardening process may be the cause. The new process has a glossy almost painted like finish.
When I try to measure the surface hardness, I get readings all over the map from 15-55 Ra to 60-75 R15N. I’m familiar with the nitrocarburizing and case hardening, but other processes that impart this glossy finish is where I need some help, and have a couple questions.
Which processes impart that glossy finish, and what are the hardness characteristics (Rockwell, depth, etc.) of that finish? How best to measure the hardness – Rockwell 15N, Ra, or other? Does the finish affect the hardness reading at all?
Newbie to this forum. : )