胀形对TC4合金环锻件残余应力及分布的影响

Residual stresses in TC4 ring forgings were tested and described using radar charts. The effects of bulging process on residual stress and its distribution along circumference were analyzed. The results show that radar charts can describe effectively the values and distributions of residual stresses along circumference for the ring forgings. And the bulging process is an effective way to adjust the residual stress in the ring forgings. For the ring forgings in the present paper, the residual stresses are compressive stresses and fluctuate in the range of -50~-150 MPa. A sharp area exists in each radar chart and is weakened after bulging process; meanwhile, the average residual stress is decreased slightly. The hoop stresses are relaxed much more than the axial and radial stresses, especially on the inner face and upper end surface with the reduction rate of about 24.8% and 20.2%, respectively. The distribution uniformity of residual stress is improved after the bulging process, except for the lower end surface.