Polarity, Pulsing, Gas, and Fluxes in the Welding Arc

  • Program
  • Room 2E East
  • September 13 2018
  • 9:30 am - 9:55 am

This presentation will discuss the role of the arc in penetration and deposition rate in welding. What we call “Voltage” during welding is in reality the combination of many voltages. Voltage loss is not proportional through the arc, with the largest fraction of voltage drop concentrated at the electrode surface and the plate surface. Polarity, pulsing, shielding gas selection, and flux chemistry have much influence on these voltages; and understanding them will help answer the questions such as “why DCEP in GTAW can melt the tungsten?”, “why AC can result in higher deposition rate in SAW and GMAW?”, “why does reverse polarity increase penetration in stick welding?”, and “why 6010 works with DCEP and 6011 with AC?” Ultimately, it will be clear that there is much more than heat input to make sense of arc welding. The good news is that a few additional concepts can help
make sense of most of it.