| 摘要 |
PURPOSE: To prevent great thermal stress from arising, by making a turbine blade or a stator blade, which is cooled by using, as a cooling medium, steam or water flowing in passages arranged inside the blade, from unidirectionally coagulated columnar crystals of Ni-based al Toys strengthened by aγ' phase mainly composed of Ni3 (Al, Ti). CONSTITUTION: A stator blade 1 manufactured by means of precise casting is cooled from inside the blade by circulating such a cooling medium as steam or water in the A direction in a cooling structure arranged inside the blade. This stator blade 1 to be cooled is manufactured by the method of unidirectionally coagulating casting with IN738LC and CM247LC, Ni-based alloys. Ni-based alloys strengthened by aγ' phase mainly composed of Ni3 (Al, Ti) are used for these two alloys. Meanwhile, in the case of a turbine stator blade, the blade is manufactured in such a manner that the growing direction C of unidirectionally coagulated columnar crystals may agree with a direction making a right angle with the flow-in direction of combustion gas, that is, the longitudinal direction of the blade. Great thermal stress can be thereby prevented from arising when cooling is carried out by the cooling medium flowing in internal coolant passages.
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