Modeling of Tensile Residual Stresses Extending More Than 5 Weld Widths From Weld Joint

Welding residual stresses around a cylindrically symmetric weld between two steel components, a necked steel forging and a uniform thickness plate, were modeled using a finite-element modeling approach. The modeling included a preheat period, a 22-pass weld and a limited cooling rate after welding, all with a sequential thermal and mechanical analysis approach. The configuration, with a J-groove bevel at the outside of the forging flange, allowed the flange to be joined to a thick steel plate. Welding residual stresses were large and tensile in the weld area. A region of surface residual tensile stress on the flange extended to the neck at more than 5 weld widths from the weld joint in a region that was not heated more than 100°C. Modifications of the welding to reduce the driving forces for residual stress changed the distribution near the weld, but did not greatly affect the remote stresses. A change of fixturing on the faying surface did significantly reduce the remote tensile stresses by more than 30%.