The reducing flame is the flame low in oxygen. It has a yellow or yellowish color due to elements (typically carbon or hydrocarbons) which would bind ("reduce") with the oxygen contained in the materials processed with the flame. The reducing flame is also called the carbonizing flame, since this flame tends to introduce carbon into the molten metal. The neutral flame is the flame in which the amount of oxygen is only enough for burning, and neither oxidation nor reducing happens. The reducing or neutral flame is useful in soldering and annealing.
The reducing flame is the flame low in oxygen. It has a yellow or yellowish color due to elements (typically carbon or hydrocarbons) which would bind ("reduce") with the oxygen contained in the materials processed with the flame. The reducing flame is also called the carbonizing flame, since this flame tends to introduce carbon into the molten metal. The neutral flame is the flame in which the amount of oxygen is only enough for burning, and neither oxidation nor reducing happens. The reducing or neutral flame is useful in soldering and annealing.