We use various types of gas welding flames to achieve different welding operations. Gas welding works by introducing oxygen and fuel gas through the torch to produce a highly concentrated flame that melts metal.
At the seam of two parts, the material melts, creating a weld pool that cools and bonds the pieces together.
The terms neutral, carburizing, and oxidizing refer to the various types of gas welding flames. The neutral flame is often used to join metal, and the carburizing flame is used to absorb carbon from the flame to the workpiece.
Oxidizing is used to join non-ferrous metals like copper and zinc; however, it is often used to cut metals. Well, in this reading, we’ll explain the various types of gas welding flames and their uses.
Let’s begin!
Read more: What is Gas Welding? Its Diagram, Types & How it Work
Types of Gas Welding Flames
Below are the various kinds of gas welding flames:
Neutral Flame
The gas welding flame releases oxygen and acetylene in a one-to-one ratio. It releases an equal amount of oxygen and acetylene. It absorbs additional oxygen from the air as it provides complete combustion.
A neutral flame is fine, clear, and well-defined. Generally, welding professionals prefer it. it produces a luminous cone indicating the completion of the flame.
Neutral flames are used to weld both ferrous and nonferrous metals such as mild steel, cast iron, copper, stainless steel, aluminum, etc.
Welders are expected to adjust to neutral before any other flame. The flame is indicated by its inner cone, consisting of a luminous cone that is bluish-white.
It is also known for its surroundings showing a light blue flame sheath or envelope. Neutral flame, which is also known as a balanced flame, is achieved by releasing excess acetylene.
A flame with a feather extension of the inner cone is produced; increasing the oxygen valve will produce the flame.
Immediately, the oxygen gas, the acetylene flame feather, disappears, leaving behind a neutral flame. The inner core tip temperature is approximately 585 degrees Fahrenheit, while the end of its outer sheath or envelope temperature drops to approximately 2300 degrees Fahrenheit.
Related: How Does Tungsten Inert Gas (TIG) Welding Works?
Carburizing Flame
This oxyacetylene flame supplies excess acetylene. Its inner core has a feather edge extending beyond it; this white feather is also known as an acetylene feather. This acetylene is 2x if it’s twice as long as the inner cone, helping to know the amount of acetylene supply.
Carburizing flame may add carbon to the welded metal of one volume. Before increasing the acetylene valve, adjust the flame to a neutral state.
The inner core will change, showing an acetylene streamer or “feather” at its end. The length of the streamer determines the level of carburization flame.
The streamer should not be more than half the length of the inner core. Three distinct flame zones clearly identify the carburizing flame.
- A clearly defined bluish-white inner cone
- White immediately cone indicating the amount of excess acetylene
- A light blue outer flare envelope.
This flare burns with a coarse rushing sound. The inner cone tip temperature is approximately 3700 degrees Fahrenheit. When we use a carburizing flame for welding, the flame absorbs carbon, causing the metals to boil.
This metal is not clear as it boils, obtains high carbon steel, becomes brittle, and is subject to cracking.
Related: What is Aluminum Gas Welding? Its Diagram & How To Perform It
Oxidizing Flame
This is the third oxyacetylene flame. When you mix one volume of acetylene with slightly more oxygen, you obtain this flame. Adjust the torch to a neutral flame, just as you would in a carburizing flame.
Next, we will increase the oxygen valve until we shorten the inner core to about one-tenth of its original length.
When properly adjusted, the flame tends to be slightly purple with a pointed inner cone. This flame is also known for its clear hissing sound.
The temperature of the oxidizing flame is approximately 6300 degrees Fahrenheit at its inner core tip. We use it to weld metals like zinc, copper, manganese steel, and cast iron.
When you apply this flame to steel, the molten metal forms and sparks off, indicating that the steel is receiving excess oxygen. It is not used for welding steel because it causes it to be porous, oxidized, and brittle.
Read more: How Does Metal Inert Gas (MIG) Welding Works?
Diagram of Gas Welding Flames
