Numerical Simulation of Stress of CADI Grinding Ball and Its Failure Analysis in Falling Ball Test

In this paper,based on the finite element analysis software ANSYS/LS-DYNA,stress field of CADI grinding ball during the falling ball test with a single drop was simulated.The results show that the peak value of shear stress appears in the area slightly deviated from the center of the contact interface while the maximum of equivalent stress is just at the center of the contact interface.Both the peak of residual equivalent stress and residual shear stress appear in the neighboring extrusion zone of collision.It is believed that surface spalling failure of the CADI grinding ball is resulted from the fatigue damage of the material that caused by the accumulation of residual stress,stress-induced martensitic transformation,work hardening,material and metallurgical quality.The existence of slag in the subsurface of the ball is the real reason that causes the spalling failure of CADI ball.