Atomic hydrogen welding

The electric arc efficiently breaks up the hydrogen molecules, which later recombine with tremendous release of heat, reaching temperatures from 3400 to 4000 °C.

The presence of hydrogen also acts as a shielding gas, preventing oxidation and contamination by carbon, nitrogen or oxygen, which can severely damage the properties of many metals.

When the hydrogen strikes a relatively cold surface (i.e. the weld zone), it recombines into its diatomic form, releasing the energy associated with the formation of that bond.

The energy in AHW can be varied easily by changing the distance between the arc stream and the workpiece surface.

This process is being replaced by gas metal-arc welding, mainly because of the availability of inexpensive inert gases.