PRODUCTION OF SQUARE STEEL PIPE

摘要

PURPOSE:To produce a straight square steel pipe by preventing bowed deformation by cap plate welding at the time of producing the square steel pipe. CONSTITUTION:Reverse strains meeting welding deformation are previously imparted to a U-shaped blank 1 prior to welding of a cap plate to the U-shaped blank 1 so as to cancel the thermal shrinkage quantity at the time of cap plate welding. As a result, the need for a large-sized press to be used for straightening the square steel pipe is eliminated. In addition, a finished product is obtd. without requiring such advanced skill as straightening by linear heating and long time.