3ロール型，2ロール型リングローリングにおける<br>変形特性の実験的研究

Abstract

Hot ring rolling is a useful process for producing large seamless rings such as bearing races for ships, airplanes and windmills. Ring rolling is classified into two types, i.e., two-roll-type and three-roll-type, by roll layout. A two-roll-type ring rolling mill is generally used for manufacturing processes. On the other hand, a three-roll-type ring rolling mill has fewer applications, and therefore has been less studied. In this study, the deformation characteristics in both types of ring rolling were investigated experimentally. It is found that the deformation characteristics near the center of the width of the ring in three-roll-type ring rolling are similar to those observed under plane strain compression. In this region, fiber flow toward the outer side is observed. It is also found that three-roll-type ring rolling shows less lateral spread and more uniform deformation than the two-roll-type process without axial rolls.