Double-U groove joint geometry
Double-U groove geometry is a symmetrical U-groove with two weld metal sides for very thick cross sections. It minimizes weld metal volume and improves thermal control on heavy components.
Physical-Chemical Mechanism of Action
The double-U groove geometry distributes the welding evenly on both sides of the joint, which reduces distortion and the stresses are absorbed more uniformly. This prevents local overheating and cooling shocks.
Metallurgical Relevance & Welding Risks
If handled incorrectly, the double-U groove can lead to uneven cooling, causing stress build-up and potential cracking. Insufficient weld metal can also lead to hot cracking or lack of fusion.
Workshop Practice & Instructions
For the double-U groove, use a uniform welding current and control the temperature in the weld zone. Make sure the weld metal is sufficient and the groove is symmetrical. An optimal cooling time is typically between 10 and 20 seconds.