| 摘要 |
<p>The process is intended for pre-forming a rail section starting from rectangular-section material (1). It comprises two phases carried out in a universal four-roller set. During the first passes, the area intended to form the web section is reduced by the horizontal rollers (2,3) whilst one of the vertical rollers (4,5) reduces the head section. - During the following passes, the horizontal rollers further reduce the web section and simultaneously reduce the sides of the head section. The other (4) of the vertical rollers reduces the foot section whilst the first (5) remains ineffective. This second phase may include passing through a duo-roller set which may alternate with passes through the universal set.</p> |
