Mfr. of long conductor with asymmetric longitudinal holes - uses progressive refining, drawing or rolling interposed by hole drilling

摘要

The multiphase drawing or rolling process with an intermediate drilling phase may be used to make hollow internally cooled conductors for industrial plant. The conductors may be of extensive length and of rectangular section, with an assymetric arrangement of continuous longitudinal holes (1). In the initial drawing or rolling phase a solid piece which approximates to the required section is made. In the second phase the longitudinal holes (1) are fashioned by e.g drilling. The section is then completed by successive rolling or drawing operations, with mandrels inserted in the drillings. The finishing phases may be supplemented by intermediate tempering.