Excessive Root Penetration
Root overhang is a weld defect where too much weld metal hangs uncontrolled on the root side. This can narrow the pipe cross-section and lead to notches.
Physical-Chemical Action Mechanism
During welding, an overhang of weld metal forms on the root side if the weld pool is not optimal. This can be caused by excessive voltage or inaccurate welding direction.
Metallurgical Relevance & Risks in Welding
A root overhang can narrow the pipe cross-section, affecting the flow capacity. In addition, it creates notches and increases the risk of cracks or stress concentrations in the material.
Workshop Practice & Action Instructions
To avoid root overhang, pay attention to correct welding direction and adequate voltage. Use a stable welding setup and adjust the welding parameters like current and voltage precisely. If needed, a backing bar can be used to prevent the overhang.