The velocity field and temperature field of liquid metal in the filling process of a heavy-duty gas turbine blade were simulated by the ProCAST software. The formation mechanism of misrun defect and the influence behavior of process parameters were described. The results reveal that the defect of misrun is caused by the excessive heat loss of liquid metal during the filling process

which is essentially attributed to the filling order

filling track and heat exchange affecting the temperature distribution of the liquid metal. In addition

the result also found that the scale of misrun defects can be improved with increasing in pouring temperature. The filling sequence and path can be changed with increasing filling rate

however not necessarily improve heat exchange status and misrun defects. The filling sequence

filling path and heat exchange of liquid metal can be fundamentally controlled by optimizing design of the gating system and reasonably controlling the casting parameters

thus effectively avoiding the defect of misrun.