The thermal fatigue fracture of engine exhaust manifold will affect its service life and engine work, to prevent and resolve this problem, finite element analysis software ANSYS was used to establish a finite element model for exhaust manifold work environment, and calculate the steady-state temperature distribution under the thermal field. Through the thermal stress analysis of manifold, identified the region most prone to the generate thermal stress and fracture, conducted failure analysis, for the existing problems analyzed the reason of thermal fatigue fracture on exhaust manifold, and provided a reliable basis for the optimization of the exhaust manifold. The thermal fatigue failure of exhaust manifold got good improvement after the structure improvement.
