Definition
An oxyacetylene flame produced with an excess of acetylene relative to oxygen, identifiable by a feathery white secondary cone surrounding the inner cone. It introduces carbon into the molten metal and is used for welding high-carbon steels, hard-surfacing, and certain non-ferrous metals.
Plain English
A welding flame with too much acetylene and not enough oxygen, which adds carbon to the metal being welded.
Context Anchor
Seen in aircraft sheet-metal and structural repair discussions involving gas welding flame adjustment.
Derivation
From 'carburize,' meaning to add carbon to a metal. The flame is named for what it does to the weld pool — it carburizes (adds carbon to) the metal as it melts.
Why Pilots Care
Using this flame during repairs can strengthen or weaken metal joints depending on the desired outcome.
Grounding Statement
Picture a gas-welding torch adjusted so the fuel gas is too rich; the flame is no longer neutral and can change the surface of the metal it heats.
Intuition Check
Do not read “carburizing flame” as just a hotter flame. It means a carbon-rich flame caused by excess acetylene.
Example Sentence 1
The technician adjusted the torch to a slightly carburizing flame before hard-surfacing the steel component.
Example Sentence 2
A carburizing flame leaves a sooty layer on the metal surface.