This week we feature a Gas Tungsten Arc (GTAW) single-sided pipe welding project.
We have excellent Xiris Automation Inc. video showcasing the ARC Specialties welder control philosophy. Our approach is to use a single computer to control motion and weld parameters. We treat the welding power supply as a simple amplifier which reproduces any wave form we generate.
We are welding nitrogen strengthened stainless so we must minimize heat input or lose nitrogen. Nitrogen is a austenite stabilizer. It also enhances weld strength. By synchronizing welding current with torch oscillation we reduce total energy input. For the same reason we automatically water quench and air dry between weld layers.
Synced current and motion is trick we first developed for welding NASCAR cams. To weld cams without melting the thin edges you must drop current on the sides of torch oscillation.
Today’s weld is a J prep narrow groove joint. To assure side wall fusion we increase current along the edges. Watch closely to see: synced pulse, automatic torch height, cold wire feed into the leading edge, wire retract and current ramp down to avoid crater cracking.
GTAW is a under used process with unique advantages for automation.