Residual Stress Measurement in Ultra-thick Electron Beam Welded Plate of Titanium Alloy

Abstract The residual stress distribution in the ultra-thick plate with a single penetrated weld was unclear now. The surface and internal residual stresses in an electron beam welded joint of 150mm thick titanium alloy plate were both measured by coupled XRD method and inherent strain theory in this study. The 3D residual stress was obtained by collecting the inherent strain data caused by welding. It was shown that the maximal welding residual stress was the longitudinal residual stress σ x . And the peak longitudinal residual stress was at the location of 50mm below the weld surface. A heat treatment of 650℃/2h was conducted for welding residual stress relaxation. The surface and internal residual stresses after heat treatment were both measured. It was shown that there was an obvious relaxation after heat treatment. The peak surface residual stress was reduced to 105MPa from 535MPa. The transverse residual stress σ y c and thickness residual stress σ z c in C-sample and the longitudinal residual stress σ x p in P-sample all approached zero.