| 摘要 |
PURPOSE:To improve the life of a hot working roll and to prevent the fracture accident thereof by inscribing many arc- or wave-shaped grooves on the surface of said roll thereby dispersing the cracks to be produced on the roll surface. CONSTITUTION:Many arc-shaped grooves 2 or wave-shaped grooves 2' are inscribed on the surface of a hot working roll 1 in a range not so deep from the surface. Many of the cracks produced on the surface of the roll 1 upon use are the cracks in the direction at right angles to the roll axis and the cracks (a) initiating from the inscribed grooves 2, etc. The other cracks (b) contact the grooves 2 as well in the process of the growth thereof and change in the axial direction of the roll. When the directions of the cracks (a), (b) are directed to the axial direction of the roll, no stresses are exerted in the direction thereof; therefore, the growth of the crack ceases and the fracture accident of the roll 1 is prevented. |
