Stability of shot-peen residual stresses in an alpha + beta titanium alloy

摘要

Shot-peen residual stress relaxation due to thermal exposure and fatigue loading was characterized in Ti-6Al-2Sn-4Zr-6Mo. Approximately 80 percent of the residual stresses were retained at 399 deg C up to 100 h. Under fatigue loading close to yield stress, retention of residual stresses was approximately 85 percent, 70 percent and 50 percent at 260, 316 and 399 deg C, respectively. Crack growth calculations demonstrate 1.5-5 X benefit in life, even for partial credit for shot-peen residual stresses.