Through-thickness distribution of residual stresses in Q345qD butt-welded steel plates

摘要

Welding residual stress measurements were performed on 16-, 40-, 60-, 80-, and 100-mm-thick, welded Q345qD steel plates. The through-thickness stresses are almost uniformly distributed in the thin specimen (16 mm). In 40 mm-thick specimen, the stresses exhibit slight fluctuations as function of thickness. The through-thickness longitudinal and transverse stresses generally exhibit C-shaped distributions in thicker specimens (60, 80 and 100 mm), while longitudinal stresses exhibit Sigma-shaped distributions in these specimens at the weld centerline. High longitudinal stress (>= 250 MPa) regions occur predominantly at the surfaces and centers of the cross sections, while high transverse stress regions occur predominantly in the surface layers. The longitudinal stress is almost always tensile at the mid-thickness regions of the welds, while the transverse stress is compressive. The longitudinal and transverse stresses distributions generally range from -250 to 550 MPa. Commonly used empirical equations for residual stresses distribution were modified to expand their range of application based on the data obtained in present work.