FORMATION OF CIRCULAR COLUMNAR BLANK MATERIAL BY FORGING

摘要

PURPOSE:To form a circular columnar material by forging by inserting a blank material between upper and lower anvils of which the surfaces in contact with the blank material have a hollow surface, rolling down the blank material and repeating the rotation and rolling reduction so that loose structural defects can be stuck by forging and that the surface-layer structure of the blank material is effectively utilized. CONSTITUTION:The diametral sectional shape of a circular columnar blank material 1 prior to forging is circular. The material 1 is formed into a square sectional shape by the first rolling reduction and is then similarly rolled down to an octagonal sectional shape; thereafter, the material is finally restored to the circular sectional shape. Working efficiency is improved by the above-mentioned method. The product having high quality is obtd. particularly from a blank roll material for cold rolling.