Analysis of low transformation temperature welding (LTTW) consumables – distortion control and evolution of stresses

Abstract

Low transformation temperature welding (LTTW) consumables have been reported to reduce the tensile residual stresses in weldments. Martensitic transformation induces compressive residual stresses and improves the fatigue resistance of welded joints. Several of these LTTW consumables have been developed at the Colorado School of Mines. This research work presents the comparisons of the experimentally and Sysweld calculated measurements for distortions and residual stresses for different plate thicknesses. In addition, residual stress evolution with time graphs were plotted to determine the amount of martensite required to promote compressive residual stresses and to calculate the time required to induce compressive residual stresses. The main aspect of this research is to analyse the behaviour of LTTW consumables in terms of distortion and residual stresses on various plate thicknesses.

Keywords:

• LTTW consumables
• Residual stresses
• Distortion
• Martensite transformation
• Sysweld simulation
• Residual stress evolution

Acknowledgements

The authors would like to acknowledge the NSF-CIMJSEA (Center for Integrative Material Joining Science for Energy Applications) and Oak Ridge National Laboratory for their support in this work. The author would also like to thank Engineering Systems International for their assistance in Sysweld and Devasco for supplying the experimental consumables for the research. Finally, one of the authors (S.H.T.) would like to thank Colorado School of Mines – Center of Welding, Joining and Coatings Research for the support received.