Acoustic Emission Detection during Welding Residual Stresses Release in 2.25Cr1Mo0.25V Steel Welds

The main goal of this study is acoustic emission (AE) measuring of residual stresses in welded structures. The welding residual stresses release in three 2.25Cr1Mo0.25V welded specimens with different heat treatment conditions were detected and evaluated during the hole drilling strain gauge measurement by AE technique. AE signals from residual stresses release were detected and analyzed for the first time. The results showed that the waveform of residual stress release signal is in a burst type and the spectral energy has the peak frequency at 147 kHz. Furthermore, the AE hits of as-welded specimen are much more than those of specimens after heat treatment due to the higher welding residual stresses. This indicates that AE is sensitive to residual stresses and could be used as a tool to monitor residual stresses release and to make evaluations on residual stresses qualitatively in the future.