We are heat treating 52100 (100Cr6) material with salt quenching.
After heat treatment we are observing red colour (powder like layer) on the surface of the parts.
If i try of wipe of with cloth it gets removed, and it is not like rust.
The process are Prewash ---- 860 C / 2 Hrs --- Salt quench...
I am facing quench cracking during plug hardening of ring with oil quench (`40C).
Hardening temp at 830C. Ring is transfered to plugging press and quenched with oil.
Material is A485-1, ring dia is 250mm and thickness is 23mm.
Crack always in the same location of undercut. Any reasons / solution ?
