Feng Zhongyuan, Ma Ninshu, Tsutsumi Seiichiro, Lu Fenggui
Joining and Welding Research Institute, Osaka University, Osaka 567-0047, Japan.
Graduate School of Engineering, Osaka University, Osaka 565-0871, Japan.
Materials (Basel). 2021 Jan 10;14(2):325. doi: 10.3390/ma14020325.
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.
我们研究了低转变温度（LTT）焊接材料是否有利于在焊缝区周围产生压缩残余应力，从而提高焊接接头的疲劳性能。进行了实验和数值研究，以分析使用LTT焊丝的多道T形焊接接头中的残余应力。结果发现，与传统焊接接头相比，LTT焊接接头的翼缘板中产生了更大的拉伸残余应力。这归因于多道焊接过程中LTT焊道的再热温度。先前形成的再热温度低于奥氏体终了温度的LTT焊道将压缩残余应力转化为拉伸应力。在再热温度高于奥氏体终了温度的区域产生了压缩残余应力，这表明LTT焊接材料更适合单道焊接。
