MANUFACTURE OF LOW CARBON MARTENSITIC STAINLESS STEEL WELDED TUBE

摘要

PROBLEM TO BE SOLVED: To manufacture a low carbon martensitic stainless steel welded tube at high speed and to obtain stable welding quality. SOLUTION: In this method for manufacturing the low carbon martensitic stainless steel welded tube by which a low carbon martensitic stainless steel strip is continuously formed into a tubular shape with plural roll-forming stands, and both edge parts to be butted of the formed tubular steel is heated and subjected to laser beam welding, fin pass rolls for holding the interval between both these edge parts at a prescribed distance and squeeze side rolls for pressurizing and butting both these edge parts are provided and also a lifting-roll device 7 is arranged between the final fin pass roll 3a and the squeeze side rolls 6. The gap G in the height direction of both edges is measured and butt welding is executed while adjusting the amount of lift with the lifting-roll device 7 based on the measured results.