Spray arc
Spray arc is a high-energy arc in which the weld metal transfers in fine droplets and spray-like into the weld pool. This allows high deposition rates and deep penetration on thicker plates.
Physical-Chemical Mechanism of Action
Spray arc produces a very bright, spraying flame by igniting gases under high pressure. The weld metal is held in this flame and transfers in fine droplets, leading to faster melting.
Metallurgical Relevance & Risks in Welding
The high performance of the spray arc allows efficient welding of thin and thick plates. However, the spraying flame can cause uneven heat transfer, leading to stresses in the weld and possible cracking. Also, the spray-like behavior of the gas can cause porosity in the weld.
Workshop Practice & Instructions
Use spray arc for thick plates and fast melting. Keep the weld metal evenly over the flame to avoid uneven heat. Use a suitable gas supply to reduce porosity.