High temperature deformation and creep behaviors of directionally solidified (DS) Inconel 738LC crystals

In this study high temperature deformation and creep behaviors of DS IN738LC were studied. The yield strength and the total elongation decreased gradually with increase of temperature from room temperature to 500 degrees C. The tensile strength and ductility increased rapidly with increase of temperature from 500 degrees C to 660 degrees C. The flow stress of Incone1738LC increases with increasing temperature up to about 600 degrees C in the presence of gamma' precipitates. For high temperature creep, the stress exponent was observed to increase from 3 similar to 9 in the lower stress region to 13 similar to 16 in the higher stress region. The significant change of the stress exponent is likely to be attributed to the inverse temperature dependence of flow stress at high temperatures in directionally solidified IN738LC.