2012 年 53 巻 613 号 p. 135-139
Hot ring rolling is a useful process for producing large seamless rings. Ring rolling mills are classified into two types, i.e., two-roll-type and three-roll-type, by roll layout. In our previous study, the deformation characteristics in three-roll-type ring rolling were investigated experimentally. It was found that the deformation characteristics near the center of the width of the ring are similar to those observed under plane strain compression. In this region, fiber flow toward the outer side was observed. In this study, numerical simulation was performed by FEM together with the ALE method for each process. FEM together with the ALE method can simulate deformation for the two types of ring rolling process. In the three-roll-type process, effective strain distributes uniformly and hydrostatic stress shows a compression state on the RD cross section. On the other hand, in the two-roll-type process, effective strain concentrates at the corner of the ring and hydrostatic stress shows less compression or tensile state. The elongation efficiency at the center of the width also shows uniform deformation in the three-roll-type ring rolling process. These results show the advantage of the three-roll-type ring rolling process for preventing internal voids and surface cracks.