Arc burning time
Arc time is the duration an electric arc remains active for heat input and material transfer. Too short an arc time can lead to incomplete welds, while too long causes overheating and distortion.
Physical-Chemical Mechanism of Action
The arc generates high temperatures through electrical discharge, forming a hot plasma. This plasma is the source of heat and mass transfer between the workpieces.
Metallurgical Relevance & Welding Risks
An arc burn time that is too short (e.g., at low voltage or poor gas supply) can result in incomplete mass transfer and incomplete weld areas. This increases the risk of cracks and distortion.
An arc burn time that is too long (e.g., at high voltage or excessive gas supply) leads to overheating of the weld, causing distortion, destruction of the microstructure, and possibly lack of weld volume.
Workshop Practice & Action Instructions
To ensure an optimal arc burn time, the voltage and gas supply must be set precisely. A typical arc burn time is about 0.5 to 1 milliseconds per weld pass. If you have issues with the burn time, first check the voltage, then the gas supply.