| 摘要 |
PURPOSE:To improve the wear resistance in edge parts and to improve the service life over the entire part of the roll by subjecting the surface in the barrel part of the roll to Cr plating and plating the parts of the surface near the parts where the edges of a steel sheet pass to the plating hardness higher than the plating hardness in the other parts. CONSTITUTION:The relation between the surface hardness of the roll and abrasion wear of the roll 2 is such that the abrasion wear decreases with an increase in the surface hardness. The relation is thus nearly linear. A lead electrode 4 is, therefore, used to increase the hardness in the edge parts of the roll for rolling having the large wear resistance. The surface in the hatched parts of the lead electrode 4 is coated by an insulator 41 and only the parts 42 corresponding to the edge parts of the roll 2 are not covered with the insulator and are energized. The current density in the edge parts of the roll is increased in this way and the thickness of the Cr plating is increased, by which the hardness higher than the other parts is obtd. and the wear resistance is improved. |
