Open Head Orbital Welding
Open-head orbital welding is a welding process with external shielding gas coverage for accessible pipes and thick-walled components. The welding head surrounds the workpiece.
Physical-Chemical Mechanism of Action
This process uses a continuous power source that conducts electric current through the welding electrolyte. The electrolyte is typically a molten metal chloride or oxide. The electricity dissolves metal ions from the workpiece and deposits them onto the welding electrode, forming a solid bond.
Metallurgical Relevance & Welding Risks
The external shielding gas prevents oxidation of the metal during welding. Without sufficient gas coverage, the workpiece can oxidize at the weld, leading to weak spots and cracks. Incorrect current or temperature can cause uneven distortion or excessive cooling, which also contributes to cracking.
Shop Practice & Action Items
Use a continuous power source with a suitable electrolyte. Make sure the shielding gas coverage is sufficient to protect the entire workpiece. Hold the welding electrode firmly so it fully surrounds the workpiece and avoid uneven distortion by keeping current and temperature constant.