Undercut Prevention via Geometry
The groove angle is chosen so that the heat input is evenly distributed across the weld. This prevents sharp transitions and reduces the risk of undercut.
Physico-chemical mechanism of action
The heat input released during welding can cause local heat shocks. A sharp transition between the base material and the weld reinforcement can concentrate this energy and lead to notches at the weld toe.
Metallurgical relevance & risks when welding
A sharp groove angle can lead to uneven heat input distribution and local heat shocks, which promotes the development of notches at the weld toe. This can impair the mechanical properties of the weld and cause cracks.
Workshop practice & instructions
To avoid notches at the weld toe, the groove angle should be selected so that the heat input is evenly distributed over the weld. This can be achieved through optimized geometry and appropriate welding parameters. Recommended values for the groove angle vary depending on the material and base metal, but in general they should be between 60° and 75°.