In order to reduce the lead time of developmental stage and increase the reliability of the forging process of turbine disk, it is effective to predict the transformation of microstructure during the forging stage. In this paper, the microstructure prediction procedure for cast/wrought form alloy72OLI is introduced. To determine the parameters quantitatively, two kinds of tests were carried out. One was isothermal heating test, the other was isothermal compression test. The relational expressions between microstructure and various parameters e.g. time, temperature and strain rate were formulated for both static grain growth model and dynamic recrystallization model. Static grain growth model and dynamic recrystallization model represents preheating process prior to forging and forging process itself respectively. The models were coupled to finite element analyzing system. Furthermore pancake forging and generic shaped disk forging were carried out to verify the effectiveness of proposed prediction system. It was confirmed that the proposed prediction system has good accuracy to apply to the actual disk forging process.High performance alloys are used for turbine disks and the requirement for its properties and reliabilities are increasing for advanced aircraft engines. Alloy720LI is one of the most effective alloy for turbine disk applications because of its high creep strength and low cycle fatigue (LCF) property at elevated temperature. In fact, several engine adopt alloy720LI as turbine disk material. Alloy720LI was developed as for both cast/wrought alloy and powder metallurgy (P/M) alloy. Many investigations were performed in both regionsId. Each has advantages and disadvantages. Generally cast/wrought form is more desirable compared to P/M form from the viewpoint of cost. Advanced aircraft engine requires not only improvement of properties but also reduction of cost. Therefore cast/wrought form is worthy of being investigated further. As for properly, cast/wrought process can give excellent creep and LCF property, much the same to P/M process. But it is difficult to give such high properties in actual parts. Alloy720LI include higher alloying elements than conventional alloys e.g. alloy718 and has greater temperature and strain rate dependence on various behaviors. Especially deformation resistance and microstructure behavior are important to produce the disk. The former restricts disk size and shape, the latter is related to final mechanical properties. Various parameters e.g. temperature, strain rate, total strain etc. have to be controlled carefully to obtain desirable mechanical properties through out any portion of disk. In case of cast/wrought process, the control of such Superalloys 2003 Edited byT

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An Fe-Cr single crystal film with Cr concentration gradient (0% -13%Cr) was prepared by electron beam deposition and irradiated by 2.4MeV Cu 2+ ions at 475°C. Irradiation effects on magnetization process were investigated using a Kerr microscope. Spike domains were observed at the boundary between irradiated and unirradiated regions, and the critical magnetic field where the spike domain disappears increased above the Cr concentration of 9%. This paper shows the usefulness of combinatorial study on irradiation phenomena and demonstrates a feasibility of magnetic nondestructive evaluation of the embrittlement in Fe-Cr alloys.