Definition - What does Carburizing Flame mean?
A carburizing flame is produced when there is an excess of acetylene gas for the amount of oxygen being consumed in an oxy-acetylene mixture, producing an acetylene-rich gas.
This kind of flame is used for welding materials that do not absorb carbon.
A carburizing flame is also known as a reducing flame.
Corrosionpedia explains Carburizing Flame
A carburizing flame burns in three shades of blue—a light blue conical-shaped flame at the tip of the nozzle is surrounded by a darker blue flame, and both of these are enclosed by a layer of even darker blue.
This flame does not oxidize metal, as there is an insufficient stoichiometric level of oxygen in this flame to consume the acetylene gas. Therefore, it is called a reducing flame. This type of flame is mostly suitable to weld high carbon steel and other metallic substances which do not absorb carbon. The flame burns at 550°F.
Carburizing flames are used for welding and heating operations as well as in welding steel surfaces.