| 摘要 |
In a welded joint obtained by multilayer, narrow-groove gas-shielded arc welding of thick steel materials having a sheet thickness of 22 mm or more, setting the depth of fusion at the bottom portion of the thick steel materials to be 1.5 mm or more and the total amount of oxygen (O) and sulfur (S) contained in the weld metal to be in a range of 400 mass ppm or more to 1000 mass ppm or less yields a narrow-groove gas-shielded arc welded joint of thick steel materials that, even when using low-cost groove formation by gas cutting, plasma cutting, or the like, can effectively prevent defects due to high-temperature cracks, lack of fusion, or the like when performing highly efficient narrow-groove gas-shielded arc welding without treatment or the like of the groove face, and that also has a small amount of deposition. |
