Welding deformation produced by two-pass welding

Abstract

Multilayer welding is considered to be an accumulation of two-pass welding, and it was clarified that the basic factors of welding deformation were produced by two-pass welding. From comparison between the experimental results and numerical analysis, it was found that the numerical analysis method used in this research was very accurate to predict the welding deformation. Also, the influences of the welding heat input and the distance between two-passes on the welding deformation were examined by using the numerical analyses. As a result, it was found that the longitudinal shrinkage made from each pass was decided by the inherent strain distribution parallel to the weld line. The inherent strain distribution parallel to the weld line after two-pass welding was a larger value at one- or two-pass welding. On the other hand, it was revealed that transverse shrinkage made from each pass was decided by the integration of inherent strain distribution perpendicular to the weld line. In the case of the inherent strain distribution perpendicular to the weld line after two-pass welding, it was clarified that the inherent strain was almost same as the sum of inherent strain distribution perpendicular to the weld line made from each pass.

Keywords:

• two-pass weld
• FEM
• longitudinal shrinkage
• transverse shrinkage
• residual stress
• inherent strain

Acknowledgements

We would like to express our gratitude to Dr Mitsuru Yasufuji of Kyushu Institute of Technology for his kind assistance during this study. Part of this study was financially supported by a subvention from the Japan Society for the Promotion of Science, for which we are very grateful.

Notes

^1. Present address: Topre Co., Tokyo, Japan.

Additional information

Notes on contributors

Takaharu Fukikawa

1 1. Present address: Topre Co., Tokyo, Japan.