Research On The All-position Automatic Welding Machine Using Self-shielded Flux Cored Wire

Self-shielded flux-cored arc welding is of excellent arc stability, strong capability of wind resistance, and the weld has better slag detachability, less incomplete fusion imperfections, and don't need shielding gas in operation, so it is very suitable for field construction.Semi- automatic welding is affected greatly by human factors, especially for all-position welding. The weld of semi- automatic welding has worse continuity and more imperfections. To resolve these problems, self-shielded flux-cored welding system was designed. The system concludes welding carriage, rigid guiding orbit, wire feeder, visualization intelligent control system and welding power source. By applying the current self-shielded flux cored wire products, a lot of welding procedure tests for X70 pipeline steel was carried out, so a set of welding process parameters was developed, including travelling speed, wire feeding speed, swing width, welding current and voltage, edge retention time. With internal welding machine, the process of "internal welding machine weld root + self-shielded flux cored wire all-position automatic welding filling, capping” was established. Mechanical performance tests of the weld were carried out.Application indicated that self-shielded flux cored wire all position welding device is stable in operation; the control system is accurate and reliable. The welding process is stable, and it is able to ensure the continuity of the weld. The weld obtained has less welding joint, less internal imperfection and better external shape. The device and the process meet the standards and requirements of the pipeline construction. The technology developed was beneficial to reduce the labor intensity, the cost of welding construction and promote the level of welding equipment localization.