Bond structure of welding backing material and the root gap setting tool, as well as the backing material and the column and the diaphragm

摘要

(57) [summary] [challenge] productivity is to provide a well-mounting easy welding backing material and the root gap setting tool. The A backing material 1 to a 4-division type, as cut at the middle position of each side. This is to form the backing material by attaching a root gap setting tool in each division point.