Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire

Zhongyuan Feng; Ninshu Ma; Seiichiro Tsutsumi; Fenggui Lu

doi:10.3390/ma14020325

Investigation of the Residual Stress in a Multi-Pass T-Welded Joint Using Low Transformation Temperature Welding Wire

Materials (Basel). 2021 Jan 10;14(2):325. doi: 10.3390/ma14020325.

Authors

Zhongyuan Feng^{1

2}, Ninshu Ma¹, Seiichiro Tsutsumi¹, Fenggui Lu³

Affiliations

¹ Joining and Welding Research Institute, Osaka University, Osaka 567-0047, Japan.
² Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan.
³ School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.

Abstract

We investigated whether low transformation temperature (LTT) welding materials are beneficial to the generation of compressive residual stress around a weld zone, thus enhancing the fatigue performance of the welded joint. An experimental and numerical study were conducted in order to analyze the residual stress in multi-pass T-welded joints using LTT welding wire. It was found that, compared to the conventional welded joint, greater tensile residual stress was induced in the flange plate of the LTT welded joints. This was attributed to the reheat temperature of the LTT weld pass during the multi-pass welding. The formerly-formed LTT weld pass with a reheat temperature lower than the austenite finish temperature converted the compressive residual stress into tensile stress. The compressive residual stress was generated in the regions with a reheat temperature higher than the austenite finish temperature, indicating that LTT welding materials are more suitable for single-pass welding.

Keywords: low transformation temperature weld metal; martensitic transformation; multi-pass welding; reheat temperature; residual stress.