Cold Metal Transfer Welding Reversal Cycle
The Cold Metal Transfer Welding reversing cycle is the process in which the welding wire is retracted during CMT (Cold Metal Transfer Welding) to relieve the short circuit and ensure a spatter-free droplet transfer. This improves the quality of the weld.
Physical-Chemical Working Principle
The Cold Metal Transfer Welding reverse cycle refers to the backward movement of the welding wire during the CMT process. This backward movement ensures that the material short-circuit is thermally relieved. As a result, the material is melted and can be deposited on the workpieces in a spatter-free droplet transfer.
Metallurgical Relevance & Risks in Welding
A faulty Cold Metal Transfer Welding reverse cycle can lead to various problems. A too short or too fast backward movement can cause the droplet not to be fully released and lead to porosity. A too long or slow backward movement can lead to spatter and uneven weld seam. Furthermore, a faulty cycle can impair the strength of the weld seam.
Workshop Practice & Action Instructions
To ensure a successful Cold Metal Transfer Welding reverse cycle, the following values must be adhered to:
• Retraction time: 10 to 20 ms
• Retraction distance: 0.5 to 1 mm
• Melt time: 30 to 40 ms
These values must be precisely maintained to ensure spatter-free droplet transfer and high weld seam quality.