UTP HydroCav - UTP Schweissmaterial

The welding of copper and copper alloys
Copper
UTP 39, UTP A 381, UTP A 38
For welding jobs, oxygen free copper according to DIN 1787 (e. g. SF–Cu, SW–Cu and OF–Cu)
should be selected since these qualities have the best performance. Of particular importance are
the high heat conductibility, the high heat expansion, the tendency to attract gases when liquid
and to release these gases again when solidifying.
Depending on the size of the part to be welded, the pre-heating temperature of 300 – 700° C
may be needed. Such a pre-heating temperature should be maintained during the welding process.
The welding with shielding gas is protecting the weld pool better than oxy-acetylene welding
and reduces the tendency to porosity.
Peening of the weld deposit while still hot increases the tensile strength and improves the ductility.
On multi layer deposits, the oxide skin of the previous layer has to be removed before depositing
the next layer.
Copper-Zinc-alloys
(brass, special brass ) DIN 17660, DIN 1709
UTP 32 – UTP A 32, UTP 320 – UTP A 320, UTP 34 – UTP A 34,
UTP A 34 MR, UTP A 384
Due to zinc evaporation during welding, porosities in the welding deposit are nearly unavoidable.
TIG welding should be done with lowest possible amperage, eventually with a.c. to obtain a
cleaning effect.
For brass with Al addition, e. g. CuZn20Al (special brass 76) TIG welding (d. c.) with UTP A 34
MR and for red brass (CuSnZnPb), TIG welding with UTP A 384 is particularly suitable.
Copper-Tin alloys
(tin bronzes) DIN 17662, DIN 1705
UTP 32 – UTP A 32, UTP 320 – UTP A 320
Beside the welding with coated stick electrodes, the MIG/TIG welding is particularly suitable for
this alloy group.
The low heat conductibility requests a pre-heating from a wall thickness of > 10 mm only. The
tendency to pores is low. Mechanical properties and corrosion resistance correspond with the
identical base material.
For joining thick walled parts it is an advantage to weld from both sides simultaneously.
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