Grade:9Cr2,9Cr2Mo,9Cr2W,9SiCr,86CrMoV7,MC3A and so on Specification and sizes:210-650mm, 300-700, 400-750, 400-850, 180- ... Hardening Zone (mm) Noxious Element Noxious Element Cold-rolling roller and roller blankworking roller 210-665mm middle roller 300-700mm backup ... porosity ≤3 Genter porosity≤3 Segregation≤3 Hot-rolling roller and roller blank 400-850mm 45Cr,55Cr,42CrMo,50CrMo, 60CrMo,60CrNiMo ...