Ring rolling with variable wall thickness

Ring rolling processes today produce axisymmetric rings, wasting material, energy and labour if non-axisymmetric components such as eccentric bearing races and bossed pipe fittings are required. A new process is proposed to roll rings with variable wall thickness. In this work, roll gaps and speeds are controlled online in physical experiments to achieve a defined variable wall thickness, enabled by photogrammetry to capture the ring’s shape and position. The trials revealed two new process limits for which new analytical explanations have been developed: a maximum rate of change of thickness around the circumference and a loss of circularity.The first author is supported by an EPSRC I-Case Studentship (12220703), with Primetals Technologies Ltd. Dr. Arthington and Prof. Allwood were supported by EPSRC grant EP/K018108/1.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.cirp.2016.04.00