Flat friction stir spot welding of low carbon steel by double side adjustable tools  

作　　者：Xiaopei Wang Yoshiaki Morisada Hidetoshi 

机构地区：[1]Fujii Joining and Welding Research Institute,Osaka University,11-1 Mihogaoka,Ibaraki,Osaka 567-0047,Japan

出　　处：《Journal of Materials Science & Technology》2021年第7期1-9,共9页材料科学技术（英文版）

基　　金：financially supported by the New Energy and Industrial Technology Development Organization (NEDO) under the “Innovation Structural Materials Project (Future Pioneering Projects)”。

摘　　要：2 mm low carbon steel plates were successfully welded by the flat friction stir spot welding(FSSW) using double side adjustable tools, by which the keyhole formed in the conventional FSSW was eliminated and a flat surface on both the top and bottom sides of the welded joints was obtained. In addition, the hook shape usually generated in the conventional FSSW was eliminated by this technique, and the unbonded interface was parallel to the surface of the sheets. Owing to the enlarged bonded interface width by eliminating the keyhole and the intermixed interface by the adjustable probe, the plug fracture occurred under all the welding conditions in the present study. Due to the suppression of the thickness thinning and elimination of the hook shape, the joint performance was improved in the plug fracture mode. The shear tensile performance was considered to strongly depend on the microstructure in the tip area of the unbonded interface and the maximum shear fracture load of 23.0 kN was achieved in this study.

关 键 词：Friction stir spot welding Interface structure Low carbon steel Mechanical properties Microstructure 

分 类 号：TG453.9[金属学及工艺—焊接]