Autogenous welding is a form of
welding in which the filler material is either supplied by melting the base material or is of identical composition.
The weld may be formed entirely by melting parts of the base metal, and no additional
filler rod is used.
There is some variation in the use of this term. Those bodies concerned with teaching the craft skill of welding tend to define it as using no filler rod, i.e. the technique is based purely on the base metal. Those concerned with the welded joint's
metallurgy
Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.
Metallurgy encompasses both the sc ...
may make no distinction between a filler rod and the base metal, provided that the final metallurgy is identical.
Most welding processes may be either autogenous or use additional filler. Some are characteristically autogenous and avoid filler. Some
arc welding processes, including such major process such as
manual metal arc (stick) welding and
MAGS (wire-feed) welding, cannot be used autogenously, as they rely on the consumption of a filler rod to provide the arc.
Some processes are typically autogenous. These include some
gas welding processes such as
lead burning (although fillers may optionally be used) and
oxy-acetylene welding in some positions, such as
seam welding the edges of two overlapping sheets.
Resistance welding, both
spot welding
A spot welder
Spot welding (or resistance spot welding) is a type of electric resistance welding used to weld various sheet metal products, through a process in which contacting metal surface points are joined by the heat obtained from resistance ...
and
seam welding, is inherently autogenous, as there is no convenient way to apply a filler.
Friction and
laser welding have similar restrictions.
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. Silicon may also be used as an additive to reduce this loss.
A few materials, such as the
HY-80 series of high-strength steels, require a non-autogenous process to control their metallurgy.
However, advanced processes, such as
hybrid laser arc welding, have been used to achieve the same effect autogenously.
References
{{Reflist, refs=
[{{Cite book
, title=The Welding, Brazing and Soldering of Copper and its Alloys
, publisher= Copper Development Association , location=England
, id=CDA Publication Nº47
, origyear=1952
, edition=4th
, year=1956
, ref={{harvid, Welding, Brazing and Soldering of Copper and its Alloys, 1952
, page=29
]
[{{Cite journal
, last=Roepke, first=C
, date=August 2009
, title=Hybrid Laser Arc Welding of HY-80 Steel
, url=https://app.aws.org/wj/supplement/wj0809-159.pdf
, journal=Supplement to Weld. J.
, volume=88
, pages=159–167
]
Welding