초내열합금 CM247LC의 미세조직 및 인장 특성에 미치는 진동 및 접종처리의 영향 = Effect of Vibration and Inoculation during Casting on the Microstructure and Tensile Properties of Superalloy CM247LC

다국어 초록 (Multilingual Abstract)

Effects of vibration(V) and inoculation(I) during casting on the microstructure and tensile properties of nickel-base superalloy CM247LC were investigated. The vibration treatment with a frequency of 10 ㎐ was effective to refine the grain size and decrease the microporosity level to some extent. The vibration treatment for the inoculated mold developed the grains of the casting into fine equiaxed grains compared with columnar grains of the casting with vibration free inoculated mold. The existing phases of CM247LC alloy such as finely dispersed cuboidal γ', MC, and grain boundary precipitates were not influenced by the vibration and/or inoculation treatment. The fine equiaxed grained CM247LC had excellent tensile properties compared with those of the columnar grains. The tensile behavior of CM247LC alloy at 760℃ showed different aspects with respect to the grain size change and which was carefully analyzed by fractographic investigations.