When an icy-acetylene flame has no excess acetylene or oxygen, it is called?

A flame characterized as having no excess acetylene or oxygen is termed a neutral flame. In welding, a neutral flame is produced when the proportions of acetylene and oxygen are balanced, resulting in a clear, defined inner cone and a light blue outer envelope. This balance allows for the most efficient combustion of the gases, producing optimal temperatures for welding without altering the chemical composition of the pool of molten metal, which is crucial for maintaining the integrity of the joint being welded.

In contrast, an oxidizing flame contains an excess of oxygen, which can lead to oxidation of the material being welded. A carburizing flame, on the other hand, has an excess of acetylene, which can introduce carbon into the weld and potentially weaken it. A reducing flame is a term less commonly used in this context but generally refers to gasses used in processes that remove oxidizing agents. These other flame types have distinct characteristics and applications that do not match the balanced nature of a neutral flame.