Newly Proposed HAZ Toughness Evaluation Method of Structural Steel for Building and The Result of Evaluation by Its Application

Abstract

This paper is intended as an investigation of the useful method of HAZ toughness evaluation and describes the results of toughness estimation for various structural steels for buildings, including JIS G 3136 SN steel. According to the experiment of fracture in the vicinity of beam-to-column connection, it often initiates near the root welding pass or finishing welding pass. Therefore, the new HAZ toughness evaluation method was proposed using one-bead welding to duplicate the coarse grain region, by taking notice of the grain-coarsened region in HAZ of the last welding pass. The HAZ toughness of SN steels and various high quality steels was estimated using one-bead method, and each exhibited the absorbed energy of more than 27J. Finally, it was examined to formulate the relationship between the HAZ toughness and the chemical compositions.