The Ignition Phenomenon and Mechanism of Welding Spatters Under Different Current Intensities

The ignition of combustible materials by electric welding spatters represents a significant cause of fires in welding operations, and the current intensity is a sensitive factor that affects the ignition capacity of welding spatters. In this work, the influence of different current intensities on the physical properties and ignition capacity of welding spatters on common combustible materials was investigated, and the ignition mechanism of electric welding spatter was also explained by means of the hot-spot theory. The results indicated that the splash range, the total generated quantity, the maximum diameter, and the temperature of electric welding spatters increased with the enhancement in current intensity. Furthermore, a higher current intensity was associated with a greater likelihood of producing irregular spatter particles. The probability of ignition of electrode welding spatters was found to be sensitive to their physical properties, exhibiting a non-linear increase with increasing current intensity. At a current intensity of 360 A, a surge in both the physical properties and ignition capacity of the spatters was observed, which is attributed to the coupling of a reduction in the critical hot-spot radius and an unstable pulsation in the arc.