Luo, Y.; Jiang, W.; Chen, D.; Wimpory, R.C.; Li, M.; Liu, X.: The repaired weld residual stress in tube to tube-sheet joint by neutron diffraction measurement and finite element method. Journal of Pressure Vessel Technology 140 (2018), p. 021404/1-8

Repair welding is a popular method to repair the leakage zone in tube-to-tubesheet joint of shell-tube heat exchangers. But the repaired residual stresses are generated inevitably and have a great effect on stress corrosion cracking (SCC). In this paper, the effects of repair welding on residual stress were studied by finite element method (FEM) and neutron diffraction measurement. The original weld residual stresses by FEM have a good agreement with neutron diffraction measurement results. After repair welding, the transverse residual stresses merely have on changes while the longitudinal residual stresses are increased in the repair zone. In non-repair zone, both the transverse and longitudinal stress are decreased. The repair welding times have little effect on residual stress distribution. With the increase of welding length and heat input, the residual stresses increase. Repair opposite to the original welding direction is recommended because it reduce the residual stress to the minimum.