Installation and commissioning of a
30 x 4m gantry Crawford Swift
‘Powerstir’ FSW machine hs been
completed by PTG Heavy Industries,
in a joint project with China
Friction Stir Welding Centre.

The Powerstir machine has played
its part in manufacturing railway car
bodies similar to those used in the
‘Harmony’ high speed train. The
machine produced what is believed
to be the longest single FSW railway
panel weld in China at over 15m.

In simple terms, FSW is a ‘solid
state’ welding process which joins
materials by plasticizing and
consolidating the material around
the joint line. No melting takes place
and the final result is a fine-grained,
hot-worked weld with no entrapped
oxides or porosity.

With speeds to 2000mm/min,
FSW is a speedy alternative to
conventional welding. The process
gives low distortion even in long
welds, good mechanical properties –
established by rigorous fatigue, tensile
and bend testing – with no fumes,
porosity or spatter. Energy-efficient,
it produces excellent joint strength
and weld appearance with no postweld
grinding.