Determination of Smoothing Zone Conical Angle of Rotary Piercing Plug

Improvement of the hollow bloom wall thickness uniformity is regarded as the basis for improvement of the finished tube wall dimensional accuracy. And a properly determined conical angle of the plug smoothing zone is a critical condition to ensure satisfactory wall uniformity resulting from the rotary piercing process. Also discussed are relevant issues concerning use of the equation of piercer roll opening to determine the said conical angle.