HIGH EFFICIENT WELDING FOR HEATTRESISTANT PIPE

摘要

PURPOSE:To manufacture long heat-resistant pipe with high efficiency by rising welding speed by making one-layer and one passage TIG welding while butting short pipes and sending hot wire. CONSTITUTION:An one-layer and one passage TIG welding is made while butting the heat-resistant short pipes 1a and 1b with narraw beveling width, directing the electrode 2 and shield gas nozzle 3 to the baveling, and sending the hot wire. In this case, if the diameter of electrode is 3.2mm and the diameter of wire is 1.2mm, better welding result can be obtained when the root height is sent to about 2.4 to 3.2mm, the bottom width of beveling is set to 5.5 to 6.0mm, the curvature of beveling bottom is set to 4.0 to 5.0, and the angle of beveling in sent to about 4 to 8. With this method, it is possible to rise the speed of welding, secure sound and proper root running, and prevent the occurrence of imperfect fusion and undercut. Thus, joint sufficiently burable against severe conditions can be obtained.