Ky. Bae et al., A STUDY OF MECHANICAL-STRESS RELIEF (MSR) TREATMENT OF RESIDUAL-STRESSES FOR ONE-PASS SUBMERGED-ARC WELDING OF V-GROOVED MILD-STEEL PLATE, Proceedings of the Institution of Mechanical Engineers. Part B, Journal of engineering manufacture, 208(3), 1994, pp. 217-227
The heat-transfer and thermal stress distributions in one-pass submerg
ed arc welding (SAW) were numerically determined using the finite elem
ent method (FEM) for a V-grooved rectangular steel plate in which the
weld preparation was filled during welding. A two-dimensional non-line
ar heat-transfer analysis was performed for a transverse section of th
e plate. This was followed by a thermo-elasto-plastic transient therma
l stress analysis, assuming plane strain to be constant for the same m
odel section. The same stress model was used to simulate a mechanical
stress relief (MSR) treatment of the plate. This has frequently been u
sed in the fabrication of large pressure vessels instead of post-weld
heat treatment (PWHT). In this way its effect in reducing the residual
stress in the welded plate was investigated. MSR was simulated by enf
orcing a constant displacement loading in the welding direction. The s
olution of the thermal stress analysis showed that it was possible for
the residual stress around the weld centre to be accurately estimated
by accurate modelling of the dilution of the filler metal in the fuse
d zone of the base metal. The conclusion derived from the MSR simulati
on was that it could quantitatively predict the effect of reducing the
residual stress in the welded plate. Only limited experimental data w
ere available. The mechanism of stress reduction was plastic straining
in regions of high residual stress. The amount of stress reduction at
the weld centre had a linear relationship to the magnitude of the ext
ernal stress relieving load. The numerical results for the MSR simulat
ion agreed fairly well with experimental ones obtained from the MSR te
st performed on a welded plate.