Autogenous welding

[1] The weld may be formed entirely by melting parts of the base metal, and no additional filler rod is used.

Some alloys are prone to changing their composition when heated, particularly a loss of zinc from brass by its evaporation as vapour.

In these cases, an excess of 2–3% extra zinc may be provided in the filler rod to compensate.

[2] A few materials, such as the HY-80 series of high-strength steels, require a non-autogenous process to control their metallurgy.

[3] However, advanced processes, such as hybrid laser arc welding, have been used to achieve the same effect autogenously.