Evaluation of Forging Process Induced Residual Stress in Aluminum Die Forgings

Abstract Forging processes include various steps to attain favorable material properties such as heat treatment, rapid quench, cold work stress relieving, and artificial aging. These steps, however, also contribute to bulk residual stress. Excessive bulk residual stresses cause a wide of problems, including part distortion during machining and in use, reduced crack initiation life, increased crack growth rates, and an overall reduction in part life. This paper summarizes recent work aimed at measurement-based assessment of bulk residual stresses in cold-compressed aluminum die forgings. The results show that forging process induced residual stress is a repeatable phenomenon with RMS repeatability less than 5% of yield.