Shielding gas coverage
Shielding gas coverage protects the molten metal and the arc from oxidation by ambient air. It prevents porosity, improves weld strength and toughness.
Physical-chemical operating principle
The shielding gas coverage forms a tight sphere around the molten metal and the arc. It shuts out the surrounding air, preventing oxidation of the metal and suppressing porosity.
Metallurgical significance & welding risks
Without shielding gas coverage, the molten metal oxidizes quickly, leading to porosity. This can significantly impair the strength of the weld and cause cracks. Good coverage ensures a clean weld with high toughness.
Workshop practice & instructions
Always use a tight shielding gas coverage when welding metal. Make sure the coverage encompasses the entire arc and the molten metal. For metals that oxidize easily, like steel or nickel, a particularly strong coverage is essential.