| 摘要 |
PURPOSE:To allow the easy and stable control of the surface roughness of the drum after the predicting a change in the surface roughness by ironing prior to the, then lathing the surface of a metallic tube stock for the drum. CONSTITUTION:The roughness of the drum after the is preferably specified to 0.5 to 1.0mum max. roughness in order to obtain good characteristics. The roughness of the tube stock by the lathing after the is preferably specified to 3 to 10mum max. roughness if the desirable surface roughness of the drum and the ironing ratio (60 to 75) of ordinary ironing are taken into consideration. The reasons thereof lie in that the surface of the drum after the ironing is an excessively mirror finished surface and there is the problem of poor working efficiency, if the surface roughness is below 3mum. There is the problem that the distinct traces of the lathing remains on the surface of the drum if the surface roughness exceeds 10mum. The 3 to 10mum range is, therefore, set as the desirable range. Further, the max. roughness is more preferably specified to 5 to 7mum for the same reasons. |
