The mathematical model of the directional solidification process of single crystal superalloy blade was established based on the finite element method. The temperature field

temperature gradient and cooling rate were simulated at different with drawal rates. The results indicate that when the with drawal rate is 7.2 mm/min

the mushy zone of the blade is wider

and the isotherm inclination is greater than that of 3.6 mm/min and 4.5 mm/min. With the withdrawal rate increasing

the temperature gradient G

L

of the solid-liquid interface is decreased

and the temperature gradient on the inside of the spiral is larger than that on the outside. The withdrawal rate has little effect on the cooling rate in the starter block of grain selector and blade

while the cooling rate in the back block is increased with the withdrawal rate increase. Meanwhile

the nucleation and growth were simulated by coupling the temperature field and CAFé module to investigate the effect of withdrawal rate on the stray grains formation. The results reveal that stray grains are generated at the edge of the platform when the withdrawal rate is 7.2 mm/min

and the complete single crystal are generated when withdrawal rate is 3.6 mm/min or 4.8 mm/min.