| 摘要 |
PURPOSE:To make the development of crack difficult and to improve service life of a roll and the productivity by arranging porous layer composed of metal and/or ceramic on barrel surface in the roll. CONSTITUTION:By arranging the porous layer 3 on the barrel surface 2 in the roll body 1, as stress is relieved with pores 4 in the porous layer 3, the thermal stress on the barrel surface 2 in the roll body 1 does not become high. Further, in the case the crack develops, this stops at pore part and in the case the crack further propagates, this propagation requires long time and propagates along circumference of the pore part and the propagating force is gradually attenuated and made to little. As the whole, crazing-like short hair cracks are developed and as the large propagated grown crack is not developed, the service life of roll is improved and breakage accident of the roll caused by propagated growth of the crack can be reduced. By this method, the working rate in an equipment using the roll is improved, and the productivity can be improved. |
