基于熔池受力的全位置STT打底焊分段工艺

Subsection process of all-position STT backing welding based on the force in molten pool

油气管道在全位置焊接时通常按照固定角度机械化地进行分段,此过程中,熔池容易发生失稳流淌而导致焊缝成形不良。文中对管道全位置焊接过程中的熔池受力进行了分析,建立了一种基于熔池径向力变化的新型分段工艺,以解决全位置焊接时管道内、外壁成形不良的问题。通过对220 mm×10 mm×400 mm的X70管线钢采用STT打底焊试验发现,该分段工艺抑制全位置焊接时的熔池失稳流淌问题有良好效果,且内壁成形更加平滑美观,对于管道自动焊接过程中的分段问题具有一定的参考价值。

When oil and gas pipelines were welded in all-positions,on which subsection was usually carried out mechanically at a fixed angle.During this process,the molten pool was prone to instability and flow,resulting in poor formation of weld.The force of the molten pool during the all-position welding process was analyzed in this paper,and a new subsection process based on the change of the radial force of the molten pool was established to solve the problem of poor formation in the inner and outer walls of the pipeline during all-position welding.Through the STT bottom welding test for 220 mm×10 mm×400 mm X70 pipeline steel,it was found that this subsection process had a good effect on suppressing the instability and flow of the molten pool during all-position welding,and the inner wall formed more smoothly and beautifully,which was suitable for automatic pipe welding.The subsection problem in the process had a certain reference value.