What is the correct action when brazing to prevent oxidation?

Using nitrogen during brazing is essential to prevent oxidation of the base metals and the filler material. Oxidation can occur at high temperatures, which is common during the brazing process. When metals are heated, they can react with oxygen in the air, forming oxides that can adversely affect the strength and integrity of the joint.

By using nitrogen as a shielding gas, you create an inert atmosphere around the brazed joint. This inert environment significantly reduces the likelihood of oxidation taking place. Nitrogen, being an abundant and inert gas, helps in pushing out the oxygen and provides an additional layer of protection, ensuring a clean and strong bond.

In terms of context, there are situations where oxidation protection might not be necessary—such as with certain types of soldering or when using specific metals that are less prone to oxidation. However, for brazing, particularly with more reactive metals, utilizing nitrogen is a best practice to ensure a successful and reliable metal joining process.