The contoured cross section rings, which are made of titanium alloys and superalloys, are in general used for jet gas-turbines of air plane. But these rings take a lot of machining hours because they are finished from simple square cross sections by machining, and give low yields of the materials. As the results, they are high cost. In order to solve these problems, the new forming machine, which is named Spinning and Rolling -- Hot (SRH) process, has been developed and established at Sibukawa Plant of Daido Steel Co., Ltd. in 1994. This machine is composed of a mandrel, a flat roll, a spinning roll and in-line heating system for ring, and it is possible to form the contoured cross section rings by ring rolling (deformation of dia-metrical expansion) and spinning (deformation of widthwise expansion) at constant high temperature. The characteristics of SRH forming method are as follows. (1) Near net shaped ring can be made with deformation of diametrical and widthwise expansion. (2) SRH forming method does not require exclusive tools for each item. And it is suitable for production of small lot and diversified ranges. (3) For materials hard to work by cold forming, such as titanium alloys,
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