Which flame type is characterized by an excess of oxygen?

The flame type characterized by an excess of oxygen is the oxidizing flame. In an oxidizing flame, the ratio of oxygen to fuel exceeds the stoichiometric balance required for complete combustion. This results in a hotter flame that can effectively oxidize metals and enhance cutting processes. The presence of excess oxygen produces a sharp, well-defined inner cone of the flame, generally indicating that the reaction is more intense and can lead to oxidation of the material being cut.

In contrast, a neutral flame has a balanced ratio of oxygen and fuel, making it suitable for welding and cutting without altering the properties of the metal. A carburizing flame, on the other hand, has an excess of fuel compared to oxygen, which can lead to the addition of carbon to the molten material. The reducing flame is similar to the carburizing flame in that it also contains excess fuel, but it is primarily used to prevent oxidation of certain metals or metal oxides during welding processes. Understanding these flame types is crucial for choosing the appropriate flame for specific cutting or welding applications.