Metaaloverdrachtreactie

Metaaloverdrachtreactie, also known as metal transfer, is a phenomenon observed in welding processes, particularly in Gas Metal Arc Welding (GMAW). It describes the process by which molten metal from the welding electrode is transferred to the workpiece. The manner of this transfer significantly influences the characteristics of the weld, including its appearance, penetration, and spatter generation.

There are several distinct modes of metal transfer, each occurring under specific combinations of welding parameters such as voltage, current, shielding gas composition, and wire feed speed. The primary modes include short-circuiting transfer, globular transfer, spray transfer, and pulsed spray transfer. Short-circuiting transfer occurs at low voltages and currents, where the electrode periodically touches the weld pool, creating a short circuit. Globular transfer is characterized by larger molten droplets detaching from the electrode and falling into the weld pool, often leading to significant spatter. Spray transfer, achieved at higher voltages and currents with suitable shielding gases, involves fine molten droplets being propelled across the arc in a spray-like fashion, resulting in a smooth weld bead and minimal spatter. Pulsed spray transfer utilizes a controlled pulsing of current to achieve the benefits of spray transfer at lower average currents, making it suitable for welding thinner materials and out-of-position welding. Understanding and controlling the metal transfer mode is crucial for achieving high-quality welds.