油气长输管道全位置自保护药芯焊丝自动焊接技术

A technology of automatic welding in long-distance pipelines by use of all-position self-shielded flux cored wires

为实现复杂施工环境下的管道自动焊接,利用自保护药芯焊丝具有较好的全位置焊接性、良好的脱渣性与电弧稳定性、未熔合缺陷低、无需保护气体、在风速小于8m/s时不需采用任何防风措施的优势,研制了管道全位置自保护药芯焊丝自动焊接系统(由安装焊炬的焊接小车、导向轨道、自动控制系统、焊接电源及送丝机等组成),应用自保护药芯成品焊丝对X80管线钢进行了焊接试验,确定了合适的自保护药芯焊丝自动焊焊接参数,进而制订了"内焊机根焊+管道全位置自保护药芯焊丝自动焊接填充、盖面焊接"的焊接工艺,并对该工艺焊缝进行了力学性能测试。试验结果表明,管道全位置自保护药芯焊丝自动焊接系统整体性能稳定,焊接过程平稳,可有效提高焊接过程的连续性与稳定性,焊接接头的内在质量、外观成形、力学性能都满足X80管线钢的焊接标准要求,且焊接时不需防风棚,可有效降低管道焊接综合成本。同时,还提出了进一步研发适合于自动焊接的专用自保护药芯焊丝的合理化建议。

In order to achieve automatic welding of pipes under complex operation environment, an automatic welding system was de- veloped by use of all-position self-shielded flux cored wires due to their many advantages, such as all-position weldability, good de tachability, arcrs stability, prevention of welding defects like incomplete fusion, unnecessary protective gases for welding nor need of any protection against wind when the wind speed is 〈8 m/s. This system consists of a welding carrier, guide rail, an auto-control system, welding source, wire feeder, and so on. Welding experiments of this system were performed on the X80 pipeline steel to de- termine proper welding parameters. The welding technology comprises root welding, filling welding and cover welding and their welding parameters were obtained from experimental analysis. On this basis, the mechanical properties tests were carried out on wel- ded joints in this case. Results show that this system can help improve the continuity and stability of the whole welding process and the welded joints＇ inherent quality, appearance shape, and mechanical performance can all meet the welding criteria for XSO pipeline steel; with windbreak fences unnecessarily needed, the overall welding cost will be sharply reduced. Meanwhile, more positive pro-posals were presented herein for the further research and development of this self-shielded flux core wires.