Nickel-based superalloys have been applied to gas turbine and aircraft jet engine parts due to superior high temperature strength and corrosion resistance. However, casting defect such as solidification cracking often occurs. In order to increase productivity of precision casting and various shape casting processes, predicting the occurrence of solidification cracking by using CAE (Computer Aided Engineering) should be essential. Therefore, it is necessary to obtain mechanical properties in the state of solid-liquid coexistence.
   In the previous reports, high temperature mechanical properties were examined but tensile rate dependency wasn't examined. In this study, high temperature (around solidus temperature) mechanical properties and tensile rate dependency of their alloy were examined by using originally developed tensile test.