WELDBONDING METHOD AND WELDBONDING STRUCTURE FOR STEEL MEMBER

To provide a weldbonding method and a weldbonding structure for a steel member such that an H-sectioned steel member can be suppressed from cracking at a flange welding part right below a scallop.SOLUTION: A welding groove 55 which extends along a width of a flange 20 is provided between a groove 40a and a diaphragm 112. At the welding groove 55, a first welding layer part 81 is formed in a first welding layer part forming process, and on the first welding layer part 81, a second welding layer part 83 having a first thick layer part 82A and a second thick layer part 82A coupled to each other right below a scallop 60A and raised from the welding groove 55 is formed in a second welding layer part forming process. On the first welding layer part 81 where the second welding layer part 33 is not provided, a third welding layer part 83 consisting of a plurality of welding layers 83a is provided in a third welding layer part forming process, so a flange welding part right below the scallop is suppressed from cracking.SELECTED DRAWING: Figure 8 【課題】Ｈ形断面の鋼部材のスカラップ直下のフランジ溶接接合部でのき裂発生を抑止できる鋼部材の溶接接合方法および溶接接合構造を提供する。【解決手段】開先４０ａとダイアフラム１１２との間に、フランジ２０の幅方向に延在する溶接溝５５が設けられ、溶接溝５５において、第１溶接層部形成工程によって第１溶接層部８１が形成され、第１溶接層部８１の上に、第２溶接層部形成工程によって、スカラップ６０Ａの直下において互いに結合し、かつ溶接溝５５から盛り上がる第１の厚層部８２Ａと第２の厚層部８２Ａを備えた第２溶接層部８３が形成され、第２溶接層部３３が設けられていない第１溶接層部８１の上に、第３溶接層部形成工程によって、複数の溶接層８３ａからなる第３溶接層部８３が設けられているので、スカラップ直下のフランジ溶接接合部でのき裂発生を抑止できる。【選択図】図８