Advanced Gas Metal Arc Welding Practice Test 2025 – Complete Exam Prep

Silicon is commonly added to GMAW electrodes as a deoxidizer due to its ability to react with oxygen during the welding process. When silicon is present, it helps to remove oxygen from the molten metal and helps to prevent inclusions that can weaken the weld. This is particularly important when welding steel and other alloys, as excessive oxygen can lead to defects such as porosity and lack of fusion. The presence of silicon in the filler wire enhances fluidity, which can improve the wettability and overall quality of the weld joint.

The other materials mentioned, while they have their own roles in welding processes, do not primarily serve as deoxidizers in the same way that silicon does. Nickel, for instance, is primarily used to improve toughness and corrosion resistance in welding filler materials. Manganese can contribute to the mechanical properties and strength of the weld but is not specifically known for deoxidizing functions. Copper is typically utilized for its conductivity and as a material for filler rods but does not have the same deoxidizing effect as silicon in GMAW applications.