Atomic hydrogen welding (AHW) Process : Introduction, Working Principle, Advantages, Dis-advantages, Applications

Introduction :

Langmuir was invented the process in the course of its atomic hydrogen studies. The electric arc efficiently breaks up the hydrogen molecules, which later recombine with an incredible release of warmth, reaching temperatures from 3400 to 4000 °C. Without a bow, the oxyhydrogen torch can only reach 2800 ° C. This is the hottest third flame after 4987 ° C and cyanogen at 4525 ° C. An acetylene torch merely reaches 3300 °C. This device could also be called an atomic hydrogen torch, nascent hydrogen torch, or Langmuir torch. Atom Hydrogen welding process is also called as Arc-Atom Welding.

Atomic hydrogen welding is a type of arc welding process where a welding gasket is performed when heating the workpiece with an arc between two electrodes and at the same time, an atmosphere of hydrogen vapor is performed in the area of welding. This stem of hydrogen gas acts as a shielding gas as well. A filler rod may or may not be used additionally.

What is the working principle of AHW?

In Atomic hydrogen welding the workpiece consists may not part of the electrical connection for completing the electrical circuit.

The arc is produced only between two tungsten electrodes.

The molecular hydrogen when passing through the electrical arc and then it is broken into atomic hydrogen form. That time it is absorbed heat energy which is supplied from the arc. The arc supplies the energy for chemical reactions.

These hydrogen atoms recombine again to form of molecular stage. This recombination takes place in the comparatively lower temperature zone as an outer zone of the arc.

This time it releases the extra amount of heat energy. This extra heat is added with main arc temperature and it produces much amount of heat, which is utilized for welding purposes. This combined heat is concentrated at high temperatures in the small volume of arc.

Fig. Atomic Hydrogen Welding (AHW)

Advantages of AHW :

• There is no flux or any protective gas needed for this welding process.
• Due to the high concentration of heat, it can carry out a high rate of fusion.
• Uniform and strong welding joints can be produced.

Disadvantages of AHW :

• The cost of welding by this process is slightly higher than with the other process.
• Welding is limited to flat positions only.
• A skilled welder is required.
• Hydrogen is a highly inflammable gas so it should be taken care of.

Applications of AHW :

• Atomic Hydrogen Welding is used in those applications where rapid welding is necessary, as for stainless steel and other special alloys.