A novel ring rolling process is proposed to flexibly produce shaped rings without circumferential ring growth, potentially saving material and energy as well as reducing upstream and downstream processing requirements. In this paper, six circumferential constraint rolls are used constrain circumferential growth and enable L-shape profiles to be developed through axial material flow, via a compressive hoop stress. Process limits were studied in 22 experiments on lead rings and a set of axisymmetric thermally coupled simulations on a high value engineering material, Inconel 718. Profile depths of 75 % of the original wall thickness were achieved in a range of rings and operating conditions, and material savings of up to 60 % demonstrated over rectilinear rolling. There was no evidence of cracking or void formation, unlike processes where under-deformed regions are stretched circumferentially and are vulnerable to cracking. In several cases a non-circular ring shape developed, limiting the achievable profile depth especially for small wall thicknesses, large reductions in thickness per pass, or large profile heights. The constraint roll forces when this ‘collapse’ occurs was studied and an upper bound predicted by a plastic hinge model. The thermal simulations showed that in all except 4 cases reheats would be required to keep within safe temperature bounds, thus suggesting an optimum reduction in thickness per pass to avoid both excessive cooling and collapse.

提出了一种新颖的环轧工艺，该环轧工艺可灵活地生产成形的环，而没有环的周向增长，从而可以节省材料和能源，并减少上游和下游的加工要求。在本文中，使用了六个周向约束辊来约束周向生长，并使L型轮廓能够通过压缩环向应力通过轴向物料流形成。在22个关于铅环的实验中研究了工艺极限，并在高价值工程材料Inconel 718上进行了一组轴对称热耦合模拟。在一系列环和工作条件下，轮廓深度达到了原始壁厚的75％，并且与直线轧制相比，材料节省高达60％。没有证据表明有裂纹或空隙形成，与变形不足的区域沿周向拉伸且容易破裂的过程不同。在某些情况下，会形成非圆形的环形形状，从而限制了可达到的轮廓深度，特别是对于较小的壁厚，每次通过的厚度大幅度减小或较大的轮廓高度而言。研究了这种“塌陷”发生时的约束侧倾力，并通过塑料铰链模型预测了上限。热模拟表明，除4种情况外，在所有情况下都需要重新加热，以保持在安全的温度范围内，因此建议每道厚度的最佳减小，以避免过度冷却和塌陷。限制了可达到的轮廓深度，特别是对于较小的壁厚，每次通过的厚度大幅度减小或较大的轮廓高度而言。研究了这种“塌陷”发生时的约束侧倾力，并通过塑料铰链模型预测了上限。热模拟表明，除4种情况外，在所有情况下都需要重新加热，以保持在安全的温度范围内，从而建议每道厚度的最佳减小，以避免过度冷却和塌陷。限制了可达到的轮廓深度，尤其是对于较小的壁厚，每次通过的厚度大幅度减小或较大的轮廓高度而言。研究了这种“塌陷”发生时的约束侧倾力，并通过塑料铰链模型预测了上限。热模拟表明，除4种情况外，在所有情况下都需要重新加热，以保持在安全的温度范围内，因此建议每道厚度的最佳减小，以避免过度冷却和塌陷。