| 摘要 |
FIELD: rolled tube production, namely working tools of piercing mills for helical rolling, possibly making tubes in tube rolling aggregates, for example with pilger mills. SUBSTANCE: roll of piercing mill includes at outlet side behind journal for bearing assembly cantilever type additional working portion with diameter consisting 0.97 - 1.0 of least diameter of outlet cone of roll barrel. Length of said portion consists 0.2 - 0.3 of length of outlet cone and it has profile preventing braking of sleeve in axial direction. EFFECT: elimination of non-uniformity of ingot deformation along cross section. 1 dwg |
