Welding thick plate inside a thick cylinder - suitable for mfg. steam generators and avoiding plate distortion during welding

摘要

A plate is welded in an axial direction in a prismatic workpiece, esp., a plate welded on its two long edges to the bore of a cylinder. The two edge are welded simultaneously, using the same conditions and submerged arc welding, starting from one side of the plate. After bow has occurred in the plate due to shrinkage, the plate is welded from the other side to remove the bow, or to create a bow in the opposite direction; welding is then continued from the first side. The joints are pref. pre-heated from both the outside a and inside of the cylinder, by using infrared radiant heaters. Used for welding plate 50 mm thick; e.g. the welding of a plate in a U-tube employed as a steam generator, where the plate divides the tube into two semicircular sections to form a pre-heating chamber.