Coarsely process and the aforementioned surface hardening treatment is done in surface which forms the irregularity aspect in process and the said ro - ru peripheral face which

摘要

PROBLEM TO BE SOLVED: To provide uniform-grain-sized flour of good quality by grinding a projecting part formed by rough surface processing, including a hardened surface layer, and subjecting the outer surface of a roll again to surface roughing. ;SOLUTION: A ground surface part 14 is formed by grinding a projecting part 11a produced as the result of surface roughing when the outer peripheral surface 2a of a roll on which a nitride layer 10 is formed is ground 50% of the depth of a biting part 11 by a grinder. Next, a new biting part 13 is formed by causing green silicon carbide 3 to bite into the ground part 14 of the outer peripheral surface 2a of the roll by a matting method. A sharp edge part 12 is thereby formed at the boundary between the remainder of the nitride layer 10 and the biting part 13. A smooth roll S with satin finished surface formed of the remainder of the nitride layer 10, the edge part 12, and the biting part 13, is manufactured.;COPYRIGHT: (C)1999,JPO