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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

After investigating the influence of various factors upon the burst in drawing under the drawing method of stainless steel production for fine wire it was confirmed that the causes giving the biggest influence lie the warm softening resistance and non-metalic inclusion and further it was found that 18 Cr-18 Ni-2.5 Mo-3.5 Cu steel was proper as austenite series stainless steel for fine wire from the result and also from the point of view of decreasing the dice wear.

ローラーバッカー式のロータリースエージング機について,その加工力学の理論解析を行なった。この結果を,加工材として鉛を用いた準静的な実験により確認し,本理論は実験結果と定性的な傾向が一致することを示した。

Investigating the cold forging characteristics of low alloy steels with low P, Si and S contents, the authors found that these steels have excellent cold forgeability.

Investigating the upsetting and compression by cylindrical dies charcateristics of carbon steels and low alloy steel, the authors made clear, firstly, the stress variation to fracture, secondly, the influence of testing conditions on fracture stress and found that the measured fracture stress coincides with the stress predicted by constant shear strain energy theory and obtained a guiding principle to measure the true workability simply.

After investigating the compression testing method against a plate type specimen by the cylindrical die as a cold forgeability which, when the history of strain during deformation is linear makes it possible to calculate the stress by the total strain theory, the underwritten facts have been confirmed.(1) The optimum conditions can be gained if a plate type specimen with thickness H, width 2H and radius of curvature of initial bulge profile (3.3∼6.6) H, is compressed by a cylindrical dies.(2) In the test under such a condition if only the tatal strain in height at fracture is measured, the local strain at the part where a crack occurs and the stress can be calculated accurately.