| 摘要 |
PURPOSE:To improve the life of a hot working roll and to prevent the fracture accident by inscribing many circular ringlike grooves of the surface of said roll thereby dispersing the cracks to be produced on the roll surface. CONSTITUTION:Many grooves 2 of a circular ringlike are inscribed on the surface of a hot working roll 1 in a range not so much deep from the surface. Many of the cracks produced in the surface of the roll 1 upon use are the cracks in the direction at right angles to the roll axis and are the cracks (a) initiating from the inscribed grooves 2. The other cracks (b) contact with the grooves 2 in the process of their growth 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 rolls, no stresses are applied in said direction; therefore, the growth of the cracks cases and the fracture accident of the roll 1 is prevented. |
