Metal separations, resulting from imperfections at the edges of the plate or skelp, parallel to the surface, which turn toward the ID or OD pipe surface when the edges are upset during welding.

• 由于钢板或管坯边缘存在的缺欠所产生的平行于对焊表面的金属分离，当焊接过程中对焊边顶锻时，这些缺欠超者管子内表面或外表面翘曲。