油气管道内焊机打底+激光-电弧复合根焊工艺

为提高长输油气管道施工质量和效率、降低施工成本,开展了应用内焊机打底+激光-电弧复合根焊工艺的高效焊接方法研究。内焊机具有根焊焊接质量高、速度快的特点,激光-电弧复合焊具有熔深比大、变形小、高速的优势,结合两种设备的优点进行焊接试验。结果表明:采用内焊机+激光-电弧复合焊工艺能够有效控制焊缝背面成型缺陷,尤其对于5:00-6:00方向,使焊缝背面内凹得到有效解决;对焊后的焊缝进行射线检测和力学性能试验,满足现有标准的要求;金相观察发现,在顶点位置焊缝钝边根部有未熔缺陷,其他位置焊缝区组织没有发现焊接缺陷。研究结果为后续激光-电弧复合焊应用于管道施工现场奠定了技术基础。

Internal welding machine rendering + laser-arc hybrid root welding technology for oil/gas pipelines

In order to improve the construction quality and efficiency of long-distance oil and gas pipelines and reduce the construction cost, an efficient welding method using internal welding machine rendering + laser-arc hybrid welding technology was developed. The internal welding machine has the characteristics of high quality and high speed of root welding, and laser-arc hybrid welding has the advantages of high penetration ratio, small deformation and high speed. Welding experiment was conducted based on the advantages of two equipments. It is indicated that by means of internal welding machine + laser-arc hybrid welding technology, the defects formed on the back of the weld can be controlled effectively, and especially the internal concave on the back of the weld in the direction of 5:00-6:00 is solved effectively. Radiographic testing and mechanical property test were conducted on the welds after welding, and it is shown that they meet the requirements of existing standards. It is revealed from the metallographic image that there are no welding defects in the weld zones, except for some incomplete penetration at the root of the weld blunt edge in the top position. The research results provide the technical foundation for the field application of laser-arc hybrid welding in pipeline construction.