Study on Toughness Test of Electro-Slag Welding of SM570 Steel

Study on Toughness Test of Electro-Slag Welding of SM570 Steel

Electro-slag welding (ESW) is one of the most efficient welding methods for manufacturing the inner diaphragms of steel box column. The box column members of the steel structural buildings in Taiwan widely use ESW to weld connections between the inner diaphragms and box columns. This study mainly discusses the toughness performance of SM570 high strength steel used to manufacture connection specimens that used ESW between the inner diaphragm and the box column. The Chapy V-Notch toughness test was carried out for three kinds of specimens, namely, the T-shape connection between the inner diaphragm and column plate in the actual box column, the cross connection used by the Japanese Institute of Architecture, and the butt connection currently in used in Taiwan. Two grades of welding materials have been used to compare three types of connection specimens. Two different thicknesses of the column plate were used to explore the effect of column plate thickness on the toughness of the T-shape connection specimen and the cross connection specimen. The test results showed that the toughness values of the heat affected zone of the column plate and the diaphragm of the three types of connection specimens are mostly less than the required 15J at -5 °C. From the toughness test results of the T connection and cross connection specimens, it was found that the thicker column plate, the greater the toughness. However, the influence of the grade of the welding material on the toughness of the heat affected zone of the column plate and the diaphragm is less significant.