REMOVAL OF EXCESS METAL, FLASH, SPATTER OR THE LIKE ON INSIDE SURFACE OF WELD ZONE IN FLASH BUTT WELDED PIPE

摘要

PURPOSE:To perform efficiently removal by using a drill for boring of which the outside diameter at the top end provided with a cutting edge is made smaller than the inside diameters of a welded pipe, the center line at the top end is deviated from the center line of the drill axis and the distance from the center line of the drill axis on the deviation side up to the edge face at the top end is specified. CONSTITUTION:The outside diameter D1 at the top end A1 provided with a cutting edge 11 with a drill for boring is made smaller than the inside diameters D3, D4 of a flash butt welded pipe 12 and the center line C1 at the top end A1 is deviated from the center line C2 of the drill axis. The distance l from the center line C2 of the drill axis on the deviation side up to the edge face of the end A1 is made slightly larger than 1/2 of the inside diameters D3, D4 of the pipe 12. The required range on the inside surface of the pipe 12 including the weld zone is cut by using such drill for boring and rotating eccentrically the end A1 by which the excess metal, flash, spatter, etc. on the inside surface of the weld zone are removed.