| 摘要 |
PROBLEM TO BE SOLVED: To provide a backing strip for butt welding of a metal sheet capable of suppressing cooling crack by delaying cooling speed, and suppressing generation of a step by suppressing thermal strain. ! SOLUTION: A backing strip for sheet welding includes a sheet loading surface 2, and a groove part 5 formed on the sheet loading surface 2 and provided with an inert gas blowout hole 4 on the bottom surface 3, and a plurality of recessed parts 5a are formed on the side wall of the groove part 5 so that the groove part side end edge of the sheet loading surface 2 has an irregular shape. Preferably, each recessed part has a circular contour shape in a plan view. ! COPYRIGHT: (C)2015,JPO&INPIT |
