Downslope Time
The current downslope time is the period during which the welding current is controlled down at the end of the weld in TIG welding. This prevents the formation of end crater cracks.
Physical-Chemical Mechanism of Action
The current down-slope time controls the slow reduction of the welding current towards the end of the welding cycle. This ensures that the metal cools slowly and does not suddenly coarsen or crack.
Metallurgical Relevance & Risks When Welding
A too rapid current decay can lead to uneven coarsening and cracking. A too slow current decay increases the risk of crater cracks at the weld end.
Workshop Practice & Instructions
The current down-slope time should be between 30 and 60 seconds, depending on the material and the weld. For steels with high zinc content, the time can be somewhat shorter (20-40 seconds). Make sure the current is reduced continuously and slowly.