INVESTIGATIONS ON THE EFFECTIVENESS OF DIFFERENT DISTORTION CONTROL METHODS IN FABRICATION OF TUBULAR PANELS WITH ONE SIDE WELDING OF ATTACHMENTS - A CASE STUDY

摘要

This article discusses the various distortion control methods and their effectiveness in controlling distortion in fabrication of tubular panels welded with attachments on one side only. The tubular panels have a plurality of tubes with fins between them and length exceeding 10 metres. The tube and fin are made of carbon steel grades. The attachment is a rod called 'wear bar' and is required to be welded to all the tubes on one side of the panel only. Owing to the heavy one side welding, severe longitudinal bending type of distortion was expected in the panels after welding. To overcome this issue, the back-to-back welding technique and the prebending technique was applied in welding the panels with attachments. These methods were applied in tandem with a suitable weld sequencing technique. It was observed that back-to-back welding technique was more effective in controlling the distortion within acceptable limits as compared to the prebending method. The back-to-back welding method also scores high in terms of ease of applicability in actual fabrication shop environments.