抄録
In order to make the best use of Ni-base single-crystal (SC) superalloys for the gas turbine blades and vanes, the finite element method was used to analyze the difference in the structural strength between SC superalloys and hypothetical isotropy (HI) for the blades and vanes of an actual turbine. As the results, it is found that the structural strength characteristic of the blades and vanes are almost the same for SC superalloys TMS-75 and for CMSX-4. The structural strength characteristic of SC superalloys is quite different from that of the HI material. For the vanes, creep rupture time of SC superalloys is extended substantially compared to that of HI material because of the anisotropy elastic coefficient of SC superalloy. For the blades, structure strength of the frangible part (leading edge and tips) has similar structural strength characteristic with that of the vanes. The structural stress of the blade root depends on the relationship between the thermal and centrifugal stresses. It is possible that when the revolution speed is higher, the stress at the blade root made of the SC superalloys is higher and the creep rupture time becomes short. Because of this phenomenon, special consideration is needed in the blades design.
