我厂制造的水井钻机方钻杆(见图1),是用φ89×8无缝钢管外包L45×45×4,L45×45×6两层角钢焊接而成的。由于工件长lOm,为了防止焊接变形,我们采取了分段对称施焊法,基本上解决了焊接变形问题。但是因工件较长,焊接时翻转较频繁,工人劳动强度大,为此,我们制了一个翻转工具(见图2)。 The square drill pipe of water well drilling machine manufactured by our factory (see Fig. 1) is welded with two angles of L45 × 45 × 4, L45 × 45 × 6 φ89 × 8 seamless steel pipe outsourcing. As the workpiece length lOm, in order to prevent welding deformation, we have taken a piecewise symmetrical welding method, basically solved the welding deformation. However, because of the longer workpieces, more frequent flipovers during welding, and greater labor intensity, we made a flip tool (see Figure 2).