PURPOSE: To prolong the service life of a roll by a simplified process by implanting boron ions into the surface layer of a roll while specifying respective ranges of a dose quantity to be implanted and acceleration energy.
CONSTITUTION: Boron ions are implanted into the surface layer of a roll for rolling to modify the roll surface. At this time, the dose quantity to be implanted is regulated to a range of 1×1015 to 3×1018 ions/cm2. Further, acceleration energy is regulated to a range of 60 to 30MeV, and ion implantation is started from a high-energy side and finished on a low-energy side. Moreover, it is desirable to regulate the concentration of Cr contained in the base material to ≤ about 10%. By the above ion implantation treatment, roll costs can be reduced and work load necessary for the replacement of rolls can also be reduced.
SUGIYAMA KENJI
IWAKI MASAYA
RIKAGAKU KENKYUSHO