What is Atomic Hydrogen Welding?
Definition: Atomic hydrogen welding is defined as a welding process in which the joining of metals takes place by heating them with an electric arc maintained between two tungsten electrodes in the atmosphere of hydrogen which acts as a shielding gas.
Atomic hydrogen welding process does not require any kind of flux.
Also the welding rod (or filler material) may or may not be used during the atomic hydrogen arc welding process.
Well, this was just an overview. Let’s see the detailed step by step procedure of atomic hydrogen arc welding.
Atomic Hydrogen Welding Process
The atomic hydrogen welding diagram is shown in the image above.
It has two inclined tungsten electrodes and the hydrogen gas is passed over from these electrodes which also provides the shielding layer to the weld.
Both the electrodes are connected with the welding power source (AC supply).
In atomic hydrogen welding process, the heat required for the welding operation is produced by the heat liberated from the combination of hydrogen atoms.
When the electric current is passed through the electrodes and workpiece, the electric arc is produced between them.
During this stage, the hydrogen gas is passed through the electric arc between the two inclined electrodes.
The high temperature of the arc dissociates the molecules of hydrogen gas (H2) into hydrogen atoms (H) and a large quantity of heat is absorbed by the hydrogen during this dissociation.
When these atoms (H) leave the arc, they recombine to form hydrogen molecules (H2) and liberate a huge amount of heat.
During this process, the oxygen gas is absorbed from the atmosphere.
The average temperature of the flame reaches around 4000 °C, and this temperature is even higher than the oxyacetylene welding flame temperature.
Hence the intense high temperature flame is obtained at the point of welding and it is generally used for rapid welding of stainless steel and other special alloys.
The hydrogen gas also acts as a shielding envelope that prevents the oxidation of workpiece as well as tungsten electrodes.
The main disadvantage of atomic hydrogen arc welding process is that it is little costly as compared to other welding processes.
But sometimes, atomic hydrogen welding is the only option for getting a perfect satisfactory weld.
I hope you have understood how atomic hydrogen welding works. Now let’s see a few applications of the same.
Applications of atomic hydrogen welding
The atomic hydrogen welding process is used for welding of most of the metals and alloys like;
- Plain carbon steel
- Alloy steel
- Stainless steel
- Other alloys, etc.
Atomic hydrogen welding torch: Image by HACNY via wikimedia commons.