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Didn't read properly again, only saw the CAST bit. I shall shuffle off in shame.From:The Welding Handbook
for maritime welders(Barvil Unitor)
SOLUTIONS: Aluminium
Metals and welding solutions:
Aluminium
Pure aluminium (Al) is a soft, easily
shaped metal with low strength.
It is characterized by low weight,
excellent corrosion resistance and
good electrical conductivity.
The strength of aluminium can be
considerably improved by the addition
of small quantities of alloy elements.
As an alloy, aluminium retains the
same appearance as pure aluminium
and approximately the same low
weight, but strength can be compared
to mild steel. Only a limited number
of aluminium alloys are considered
suitable for use on board ships.
AIMg 3 and AIMg 1 are seawater
resistant aluminium alloys. When
alloyed with copper and silicon,
aluminium can be used for the
manufacture of cast components
(silumin).
When aluminium and its alloys come
into contact with air, a refractory skin
of oxide quickly forms on the surface.
The melting point of aluminium oxide
is over 2,000°C, considerably higher
than that of aluminium, which melts
at 660°C. Unless this layer of oxide
is effectively removed during the
welding operation, the difference in
melting temperatures will make it
difficult for the metal of the workpiece to bind with the filler.
Included oxides will also reduce the
strength of the weld.
Thorough cleaning and the use of
flux is therefore essential when gas
welding aluminium.
Welding should be done immediately
after cleaning, before a new oxide
film has time to develop. Other
characteristic properties of aluminium
are a high coefficient of expansion,
good electrical and heat conductivity,
and the absence of colour change
when heated to melting point.
Filler materials for Aluminium in the
Unitor range are:
Coated electrode: ALUMIN-351N
Gas welding rod: ALUMAG-235
Wire welding: ALUMAG-W-235
For gas welding of aluminium it is
required to use a flux that removes
oxides. Use Unitor ALUFLUX-234F
for maritime welders(Barvil Unitor)
SOLUTIONS: Aluminium
Metals and welding solutions:
Aluminium
Pure aluminium (Al) is a soft, easily
shaped metal with low strength.
It is characterized by low weight,
excellent corrosion resistance and
good electrical conductivity.
The strength of aluminium can be
considerably improved by the addition
of small quantities of alloy elements.
As an alloy, aluminium retains the
same appearance as pure aluminium
and approximately the same low
weight, but strength can be compared
to mild steel. Only a limited number
of aluminium alloys are considered
suitable for use on board ships.
AIMg 3 and AIMg 1 are seawater
resistant aluminium alloys. When
alloyed with copper and silicon,
aluminium can be used for the
manufacture of cast components
(silumin).
When aluminium and its alloys come
into contact with air, a refractory skin
of oxide quickly forms on the surface.
The melting point of aluminium oxide
is over 2,000°C, considerably higher
than that of aluminium, which melts
at 660°C. Unless this layer of oxide
is effectively removed during the
welding operation, the difference in
melting temperatures will make it
difficult for the metal of the workpiece to bind with the filler.
Included oxides will also reduce the
strength of the weld.
Thorough cleaning and the use of
flux is therefore essential when gas
welding aluminium.
Welding should be done immediately
after cleaning, before a new oxide
film has time to develop. Other
characteristic properties of aluminium
are a high coefficient of expansion,
good electrical and heat conductivity,
and the absence of colour change
when heated to melting point.
Filler materials for Aluminium in the
Unitor range are:
Coated electrode: ALUMIN-351N
Gas welding rod: ALUMAG-235
Wire welding: ALUMAG-W-235
For gas welding of aluminium it is
required to use a flux that removes
oxides. Use Unitor ALUFLUX-234F
