To provide an outer face streak reduction method in a forge welded tube production process which can eliminate droop of a skelp edge part and reduce an outer face streak of a forge weld abutting part.
In a production process, in which a skelp 1 reheated to 1300-1350°C in a heating furnace 2 is formed by a vertical stand forming roll 3, a horizontal stand forming roll and blowing oxygen to both edge parts of the skelp 1 immediately before forge welding, the skelp is made into a tube by forge welding with a forge welding roll 6, an edge is formed with pressing an edge of the skelp 1 on a seam guide roll 9 of a horizontal stand forming roll pass 8, inert gas is blown immediately before forge welding. By this method, droop of the skelp edge part is eliminated and an outer face streak of the forge weld abutted part is reduced by I shaped butting of the edge. Further, quality of the forge weld abutting part is significantly improved.
SUMIMOTO DAIGO
TERADA YOSHIO
